Overview
Definition:
Parastomal varices are abnormal, dilated blood vessels that form in the tissues surrounding a colostomy or ileostomy
They typically arise as a consequence of portal hypertension, where increased pressure in the portal venous system forces blood into collateral pathways, including those adjacent to the stoma
This can lead to significant gastrointestinal bleeding.
Epidemiology:
Parastomal varices are a rare complication of ostomy surgery, reported in approximately 1% to 7% of patients with liver cirrhosis and portal hypertension who undergo stoma creation
The risk is higher in patients with more severe liver disease and pre-existing portal hypertension.
Clinical Significance:
The primary clinical significance of parastomal varices lies in their potential for life-threatening hemorrhage
Bleeding from these varices can be profuse and difficult to control, leading to significant morbidity and mortality
Prompt recognition and management are crucial for patient survival and quality of life.
Clinical Presentation
Symptoms:
Hematochezia: Bright red blood per rectum or visible at the stoma site
Melena: Although less common, dark, tarry stools can occur with slower bleeding
Abdominal pain: May be present, especially if associated with bowel obstruction or inflammation
Signs of hypovolemia: Tachycardia, hypotension, dizziness, and syncope in cases of significant blood loss.
Signs:
Visible varices: Dilated, bluish vessels may be seen around the stoma
Stomal edema: Swelling of the peristomal skin and the stoma itself
Signs of chronic liver disease: Jaundice, ascites, spider angiomata, palmar erythema.
Diagnostic Criteria:
Diagnosis is typically made based on clinical suspicion in a patient with known cirrhosis and portal hypertension who develops bleeding from an ostomy site
Confirmation is usually achieved through imaging and endoscopic evaluation.
Diagnostic Approach
History Taking:
Detailed history of liver disease, including etiology, severity, and previous management
History of ostomy creation, including indication and type
Previous episodes of variceal bleeding or treatment
Current medications, particularly anticoagulants or antiplatelets
Any recent changes in bowel habits or abdominal discomfort.
Physical Examination:
Thorough abdominal examination to assess for ascites, hepatomegaly, or splenomegaly
Close inspection of the stoma and peristomal area for visible varices, erythema, or discharge
Digital rectal examination to assess for bleeding source, though parastomal varices may not be palpable.
Investigations:
Laboratory tests: Complete blood count (CBC) to assess for anemia and thrombocytopenia
Liver function tests (LFTs) to assess hepatic synthetic and excretory function
Coagulation profile (PT/INR, aPTT) to assess clotting capacity
Imaging modalities: Doppler ultrasonography of the abdomen to assess portal vein flow and patency of shunt vessels
CT angiography or MR angiography to visualize the venous anatomy and identify varices
Endoscopy: Colonoscopy or sigmoidoscopy to visualize the stoma and peristomal area, and to rule out other sources of bleeding
Esophagogastroduodenoscopy (EGS) to assess for esophageal varices and their status
Endoscopic retrograde cholangiopancreatography (ERCP) may be considered if biliary obstruction is suspected.
Differential Diagnosis:
Other causes of stoma site bleeding: Fecal impaction
Stoma ischemia or necrosis
Peristomal infection or ulceration
Inflammatory bowel disease flare
Diverticulitis
Colitis
Hemorrhoids
Adenomatous polyps or colorectal malignancy.
Management
Initial Management:
Hemodynamic stabilization: Resuscitation with intravenous fluids and blood products as needed
Correction of coagulopathy: Administration of fresh frozen plasma (FFP), vitamin K, and platelets if indicated
Nasogastric (NG) tube insertion for gastric decompression and to monitor for upper GI bleeding.
Medical Management:
Pharmacological management to reduce portal pressure: Beta-blockers (e.g., propranolol, nadolol) are typically used to prevent variceal bleeding, but their role in established parastomal variceal bleeding is limited and primarily preventative
Somatostatin or octreotide infusions can be used acutely to reduce splanchnic blood flow and portal pressure during active bleeding, but are less effective for parastomal varices compared to esophageal varices.
Surgical Management:
Surgical intervention is often required for definitive management of parastomal varices due to the high risk of rebleeding and limited efficacy of endoscopic therapy
Shunt surgery aims to decompress the portal venous system, thereby reducing pressure within the varices
Options include:
1
Transjugular Intrahepatic Portosystemic Shunt (TIPS): A minimally invasive procedure where a stent is placed between the portal vein and hepatic vein to create a low-resistance pathway
This is often the preferred first-line treatment if technically feasible and not contraindicated by severe encephalopathy or ascites
2
Mesocaval Shunt: A surgical shunt connecting the superior mesenteric vein to the inferior vena cava
This procedure effectively decompresses the portal system but can be associated with a higher risk of hepatic encephalopathy and thrombosis
3
Distal Splenorenal Shunt (Warren Shunt): A selective shunt that decompresses the portal system by connecting the splenic vein to the left renal vein, preserving portal flow to the liver
This carries a lower risk of encephalopathy compared to mesocaval shunts but is technically more complex
4
Proximal Splenorenal Shunt: Connects the splenic vein to the renal vein without necessarily involving the superior mesenteric vein
5
Portacaval Shunt: Connects the portal vein directly to the inferior vena cava
This is a non-selective shunt with a high risk of hepatic encephalopathy
6
Ligation or Excision of Varices: In select cases, especially if the varices are localized and amenable to direct surgical intervention, ligation or excision might be considered, often as an adjunct to shunting procedures or in patients unfit for complex shunts
The choice of shunt depends on patient factors, the surgeon's expertise, and the specific venous anatomy.
Supportive Care:
Intensive monitoring of hemodynamic status and urine output
Nutritional support, including protein restriction if hepatic encephalopathy is present
Management of ascites and electrolyte imbalances
Close follow-up with hepatology and surgical teams.
Complications
Early Complications:
Bleeding: Continued or recurrent hemorrhage post-intervention
Thrombosis: Shunt or stent thrombosis leading to loss of decompression
Hepatic encephalopathy: Worsening of neurological symptoms due to diversion of portal blood
Infection: Wound infection at the stoma or surgical site
Ascites: Development or worsening of ascites
Renal dysfunction: Acute kidney injury.
Late Complications:
Progressive liver dysfunction: Worsening of underlying liver disease
Recurrent varices: Development of new varices or recanalization of treated ones
Stenosis: Narrowing of the shunt or stent
Bile duct injury: Rare complication during shunt creation
Chronic hepatic encephalopathy: Persistent neurological deficits.
Prevention Strategies:
Optimal management of underlying liver disease
Judicious use of ostomy creation in patients with known portal hypertension
Prophylactic use of beta-blockers in patients with known varices
Prompt diagnosis and treatment of bleeding episodes
Careful selection of surgical candidates and appropriate shunt procedure.
Prognosis
Factors Affecting Prognosis:
Severity of underlying liver disease (Child-Pugh score, MELD score)
Presence and severity of hepatic encephalopathy
Successful creation and patency of the chosen shunt
Presence of complications post-intervention
Nutritional status of the patient.
Outcomes:
With successful shunt surgery or TIPS, bleeding can be controlled, and recurrence rates can be significantly reduced
However, the long-term prognosis remains tied to the progression of liver disease
Survival rates vary widely and depend heavily on the factors listed above.
Follow Up:
Regular follow-up with hepatology and surgical teams is essential
This includes monitoring for shunt patency (e.g., via Doppler ultrasound), assessment of liver function, management of potential complications like encephalopathy and ascites, and surveillance for new varices.
Key Points
Exam Focus:
Parastomal varices are a rare but serious complication of ostomy in patients with portal hypertension
Shunt surgery is the mainstay of management
Understand the indications and contraindications for TIPS, mesocaval, and splenorenal shunts
Recognize that bleeding can be life-threatening and requires prompt intervention.
Clinical Pearls:
Always suspect parastomal varices in a cirrhotic patient with portal hypertension presenting with bleeding from their stoma
Doppler ultrasound is a crucial initial imaging modality
Consider TIPS as a first-line treatment option if technically feasible
The choice of shunt procedure is individualized based on patient factors and surgeon experience.
Common Mistakes:
Delaying surgical intervention in favor of less effective medical management
Inadequate resuscitation and management of coagulopathy
Failing to consider alternative causes of stoma site bleeding
Choosing a shunt procedure without considering the risk of hepatic encephalopathy.