Overview
Definition:
Massive lower gastrointestinal bleeding (LGIB) is defined as a significant hemorrhage from a source distal to the ligament of Treitz, manifesting as hematochezia or melena with hemodynamic instability requiring urgent intervention
On-table colonoscopy is a diagnostic and therapeutic tool employed during laparotomy for LGIB, allowing direct visualization and intervention at the time of surgery
Segmental resection involves the surgical removal of a specific diseased segment of the colon identified as the source of bleeding.
Epidemiology:
LGIB is less common than upper GI bleeding, accounting for approximately 10-20% of all GI bleeds
Incidence increases with age, with the majority of bleeds occurring in patients over 60 years old
Common etiologies include diverticular disease (30-50%), angiodysplasia (20-30%), colitis (15-20%), and malignancy (5-10%)
Massive bleeding requiring transfusion or operative intervention occurs in a smaller subset, estimated at 5-15% of all LGIB.
Clinical Significance:
Massive LGIB is a life-threatening surgical emergency demanding prompt diagnosis and aggressive management
Hemodynamic instability, hypovolemic shock, and the need for blood transfusions place significant strain on patient resources
Understanding the role of on-table colonoscopy and segmental resection is crucial for surgical residents preparing for DNB and NEET SS examinations, as it represents a definitive treatment strategy for intractable bleeding, preventing re-bleeding and associated morbidity.
Clinical Presentation
Symptoms:
Bright red blood per rectum (hematochezia) or dark, tarry stools (melena)
Hematochezia is more typical of distal colonic or rectal sources
melena can occur from right-sided colonic bleeds or slower transit
Symptoms of hypovolemic shock: dizziness, syncope, pallor, diaphoresis, shortness of breath, chest pain
Decreased urine output
Abdominal pain, which can be variable depending on the underlying cause (e.g., colonic ischemia vs
diverticular perforation).
Signs:
Hemodynamic instability: tachycardia, hypotension, orthostatic hypotension
Pale mucous membranes
Abdominal distension or tenderness may be present
Rectal examination may reveal gross blood or a palpable lesion
Signs of anemia: pallor, conjunctival icterus (if chronic)
Evidence of other organ system compromise due to shock.
Diagnostic Criteria:
No strict diagnostic criteria for massive LGIB itself, but the diagnosis is made clinically based on evidence of significant hemorrhage and hemodynamic compromise
Key indicators include: need for more than 2 units of packed red blood cells within 24 hours, persistent hypotension requiring vasopressors, or ongoing bleeding that cannot be controlled endoscopically or radiologically
The identification of the bleeding source is paramount and guides further management.
Diagnostic Approach
History Taking:
Focus on prior episodes of GI bleeding, history of diverticular disease, inflammatory bowel disease, malignancy, vascular malformations, anticoagulant/antiplatelet use, recent NSAID use, and previous abdominal surgeries
Ask about changes in bowel habits, weight loss, and abdominal pain
Assess for symptoms suggestive of upper GI bleed (e.g., vomiting blood) to rule out.
Physical Examination:
Thorough abdominal examination for tenderness, masses, organomegaly, and signs of peritonitis
Assess for pulsatile masses
Perform a digital rectal examination to assess for distal lesions, masses, or gross blood
Evaluate for signs of shock.
Investigations:
Laboratory tests: Complete blood count (Hb, Hct, platelets), coagulation profile (PT/INR, aPTT), liver function tests, renal function tests (creatinine, BUN), electrolytes, blood type and crossmatch
Initial imaging: Abdominal X-ray may reveal signs of obstruction or perforation
CT angiography is highly sensitive for identifying active arterial bleeding (>0.5 mL/min) and can localize the source
Nuclear medicine scans (e.g., Technetium-99m labeled red blood cell scan) can detect slower bleeding rates but are less precise localization
Colonoscopy is diagnostic and often therapeutic in stable patients
however, in massive bleeding, it may be difficult to visualize the source due to blood and stool burden.
Differential Diagnosis:
Diverticular disease (most common cause of massive LGIB), angiodysplasia, ischemic colitis, radiation colitis, inflammatory bowel disease (ulcerative colitis, Crohn's disease), malignancy (colon cancer, polyps), hemorrhoids (rarely cause massive bleeding), aortoenteric fistula (life-threatening emergency), post-polypectomy bleeding, and bleeding from an ileostomy or colostomy
In the setting of hemodynamic instability, upper GI bleed must be excluded.
Management
Initial Management:
Immediate resuscitation with intravenous fluids (crystalloids and colloids)
Aggressive blood product replacement: packed red blood cells, fresh frozen plasma, and platelets as needed to maintain hemodynamic stability and adequate oxygen carrying capacity
Two large-bore IV lines are essential
Continuous hemodynamic monitoring (heart rate, blood pressure, urine output)
Correction of coagulopathy
Nasogastric tube lavage to rule out upper GI source is crucial
Medical consultation with surgery and gastroenterology is mandatory.
Medical Management:
While definitive management is often surgical for massive bleeding, medical management focuses on resuscitation and stabilization
Use of proton pump inhibitors (PPIs) is standard practice to suppress gastric acid, especially if upper GI bleed is suspected or in patients with comorbidities
Patients on anticoagulants may require reversal agents (e.g., vitamin K, FFP, prothrombin complex concentrate).
Surgical Management:
Indications for surgery include hemodynamic instability despite maximal resuscitation, failure of endoscopic intervention, or identification of a surgical lesion not amenable to endoscopic therapy
The approach involves exploration, identification of the bleeding source (often aided by intraoperative findings), and potentially on-table colonoscopy to confirm the site
Segmental resection of the affected bowel segment is performed once the bleeding source is localized
If a specific site cannot be definitively identified, subtotal colectomy with ileoproctostomy or ileostomy may be necessary, especially if diffuse bleeding from diverticular disease is suspected
Diverting ostomy may be considered in select cases.
Supportive Care:
Close monitoring of vital signs, fluid balance, and urine output
Continuous laboratory monitoring: Hb, Hct, coagulation parameters
Early consultation with intensive care unit (ICU) if patient remains hemodynamically unstable
Nutritional support should be initiated as soon as tolerated
Pain management and prophylaxis against deep vein thrombosis (DVT) and stress ulcers are essential.
Complications
Early Complications:
Re-bleeding, anastomotic leak if resection and anastomosis performed, intra-abdominal abscess, sepsis, continued hemodynamic instability, complications of blood transfusion (TRALI, TACO), and respiratory failure
Injury to adjacent organs during surgery.
Late Complications:
Anastomotic stricture, incisional hernia, bowel obstruction, adhesions, stomal complications (if applicable), and post-colectomy diarrhea
Chronic anemia and malnutrition.
Prevention Strategies:
Meticulous surgical technique, appropriate patient selection for resection and anastomosis, adequate bowel preparation, judicious use of antibiotics, and vigilant postoperative monitoring
Early identification and management of coagulopathy
Careful consideration of diversion if risk of anastomotic leak is high
Prophylaxis against DVT and stress ulcers.
Prognosis
Factors Affecting Prognosis:
Severity of bleeding, hemodynamic stability, patient's comorbidities, success of initial resuscitation, promptness of surgical intervention, and the etiology of bleeding
Mortality rates for massive LGIB can range from 5-20%, increasing significantly with shock and comorbidities.
Outcomes:
Successful surgical control of bleeding leads to stabilization and recovery
The main long-term outcome is related to the underlying cause of bleeding and the extent of bowel resection
Patients undergoing colectomy may experience changes in bowel function
Morbidity is significantly reduced by timely and effective intervention.
Follow Up:
Close follow-up is required to monitor for recurrence of bleeding, assess for complications related to surgery (e.g., anastomotic issues, stoma function), and manage any long-term sequelae
Surveillance colonoscopies may be indicated depending on the etiology of the bleed (e.g., inflammatory bowel disease, malignancy).
Key Points
Exam Focus:
Differentiate causes of LGIB
Recognize hemodynamic instability as an indicator for urgent surgical intervention
Understand the role and indications for on-table colonoscopy
Know the surgical options for LGIB: segmental resection vs
subtotal colectomy
Be aware of the initial resuscitation priorities in massive bleeding.
Clinical Pearls:
Always rule out an upper GI bleed with an NG tube in patients presenting with hematochezia and hemodynamic instability
Prompt surgical consultation is critical
Intraoperative localization of the bleed is key
consider on-table colonoscopy if visualization is challenging
A multidisciplinary approach (surgery, gastroenterology, interventional radiology) is often optimal.
Common Mistakes:
Delaying surgical intervention in a hemodynamically unstable patient
Inadequate resuscitation
Performing an unnecessary extensive resection when a localized source is identifiable
Failure to consider and rule out upper GI bleeding
Not obtaining adequate blood products preoperatively.