Overview
Definition:
Adhesiolysis is a surgical procedure to divide or remove adhesions, which are bands of scar tissue that can form between organs and tissues in the abdomen
In the context of small bowel obstruction (SBO), adhesiolysis is performed to relieve the blockage caused by these adhesions, which are the most common cause of SBO in developed countries, particularly in patients with a history of abdominal surgery.
Epidemiology:
Adhesions form in over 90% of patients undergoing abdominal surgery
Approximately 5-10% of patients who develop adhesions will experience a small bowel obstruction requiring surgical intervention during their lifetime
The incidence of SBO due to adhesions is higher in younger individuals and those who have undergone multiple laparotomies
The incidence of mortality related to SBO has decreased with prompt surgical management but remains significant.
Clinical Significance:
Small bowel obstruction caused by adhesions is a common surgical emergency
Unresolved obstruction can lead to bowel ischemia, perforation, sepsis, and death
Therefore, prompt diagnosis and appropriate management, including surgical adhesiolysis, are crucial for improving patient outcomes and preventing life-threatening complications
Understanding the pathophysiology, diagnosis, and surgical techniques for adhesiolysis is vital for surgical residents preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Abdominal pain, typically crampy and intermittent
Nausea and vomiting, which can become feculent with prolonged obstruction
Abdominal distension
Inability to pass flatus or stool (obstipation)
Early SBO may present with passage of stool and flatus
Signs of dehydration and electrolyte imbalance.
Signs:
Abdominal tenderness, often diffuse or localized depending on the site of obstruction and presence of complications
Guarding and rebound tenderness may indicate peritonitis or bowel ischemia
Absent bowel sounds in complete obstruction, or high-pitched tinkling sounds in partial obstruction
Visible peristaltic waves in some cases
Rectal examination may reveal an empty vault.
Diagnostic Criteria:
Diagnosis is primarily based on clinical presentation and supported by imaging
The hallmark clinical features of SBO are abdominal pain, nausea, vomiting, and distension with absence of flatus or stool
Imaging studies like X-ray, CT scan, or MRI confirm the diagnosis by showing dilated loops of small bowel with air-fluid levels and a transition point
Absence of bowel sounds and significant abdominal distension are critical indicators for urgent surgical evaluation.
Diagnostic Approach
History Taking:
Detailed history of previous abdominal surgeries is paramount
Ask about the type, extent, and date of previous surgeries
Onset, character, and severity of abdominal pain
Vomiting (frequency, character, e.g., bilious or feculent)
Bowel habit changes (flatus and stool)
Presence of any known comorbidities like inflammatory bowel disease, hernias, or malignancy
Red flags include fever, severe focal tenderness, or hemodynamic instability suggesting ischemia or perforation.
Physical Examination:
A systematic abdominal examination is essential
Assess for distension, tenderness (location and character), guarding, and rebound tenderness
Auscultate for bowel sounds, noting their character (normal, hyperactive, hypoactive, or absent)
Palpate for masses or hernias
Assess vital signs for signs of shock or sepsis
Digital rectal examination to assess for distal obstruction or impaction.
Investigations:
Abdominal X-rays (supine and erect) can show dilated loops of small bowel and air-fluid levels, but are less sensitive than CT
CT scan of the abdomen and pelvis with oral and IV contrast is the investigation of choice
it can identify the level and cause of obstruction, detect complications like ischemia or perforation, and help differentiate adhesions from other causes
Laboratory tests include complete blood count (leukocytosis may suggest ischemia/perforation), electrolytes, renal function tests, and liver function tests
Arterial blood gas analysis for metabolic derangements.
Differential Diagnosis:
Other causes of SBO include internal hernias, adhesions, malignancy (intrinsic or extrinsic compression), intussusception, volvulus, Crohn's disease strictures, and bezoars
Conditions that mimic SBO include paralytic ileus, gastroenteritis, and appendicitis
The presence of a transition point on CT scan and a history of prior surgery strongly favor adhesions as the etiology.
Management
Initial Management:
Immediate resuscitation is crucial
Intravenous fluid resuscitation to correct dehydration and electrolyte imbalances
Nasogastric tube insertion for decompression and relief of nausea/vomiting
Broad-spectrum antibiotics if there is suspicion of perforation or peritonitis
Pain control with analgesics
NPO (nil per os) status.
Medical Management:
Primarily supportive, focusing on fluid and electrolyte correction and bowel decompression
Prophylaxis against deep vein thrombosis
Close monitoring of vital signs and abdominal exam
If the obstruction is partial and the patient is stable, a trial of conservative management with NG decompression may be attempted for 48-72 hours
If symptoms do not improve, surgical intervention is indicated.
Surgical Management:
Indications for open surgery include signs of strangulation or perforation, failure of conservative management, or complete SBO
The procedure is an exploratory laparotomy followed by adhesiolysis
The surgeon meticulously dissects the small bowel, identifying and dividing the obstructing adhesions
Care is taken to avoid injury to the bowel
If bowel viability is compromised (ischemic or necrotic), resection and anastomosis are required
The goal is to restore bowel continuity and relieve the obstruction.
Supportive Care:
Postoperative care includes continued IV fluids, pain management, gradual reintroduction of oral intake as bowel function returns, and monitoring for complications
Mobilization as tolerated
Nutritional support, including parenteral nutrition if prolonged ileus is anticipated
Early ambulation and incentive spirometry to prevent pulmonary complications
Monitoring of wound healing.
Complications
Early Complications:
Bleeding, infection (wound infection, intra-abdominal abscess), injury to adjacent organs (e.g., ureter, bladder, major vessels), unintentional enterotomy (perforation of the small bowel), bowel ischemia or necrosis if diagnosis/intervention is delayed, anastomotic leak if bowel resection was performed, prolonged ileus, deep vein thrombosis, pulmonary embolism, and anesthetic complications.
Late Complications:
Recurrent small bowel obstruction due to new adhesions forming postoperatively, incisional hernia, chronic pain, and bowel strictures
The risk of recurrent obstruction is significant, with estimates ranging from 10-30% after a first episode
Risk factors for recurrence include extensive adhesions and multiple abdominal surgeries.
Prevention Strategies:
Minimizing intra-abdominal surgery, using minimally invasive techniques (laparoscopy) where possible, meticulous surgical technique to reduce tissue handling and foreign body material, judicious use of abdominal drains, and considering the use of adhesion barriers (though their efficacy is debated)
Postoperative care aimed at promoting early ambulation and reducing intra-abdominal sepsis can also help.
Prognosis
Factors Affecting Prognosis:
The main factors affecting prognosis are the duration of obstruction, the presence and extent of bowel ischemia or perforation, the patient's overall health status, and the promptness of diagnosis and intervention
Patients with simple, uncomplicated SBO have a good prognosis with timely surgery
Those with ischemic bowel or perforation have significantly higher morbidity and mortality.
Outcomes:
With successful adhesiolysis and no complications, most patients recover well and return to normal diet and activity within weeks
For patients requiring bowel resection due to ischemia, recovery can be prolonged, and the risk of complications is higher
Mortality rates for SBO have decreased but are still around 3-5% for uncomplicated cases and can exceed 30% for complicated cases (perforation or strangulation).
Follow Up:
Follow-up includes monitoring for signs of recurrent obstruction, incisional hernia, and chronic pain
Patients should be educated about the symptoms of recurrent SBO and advised to seek prompt medical attention
Routine follow-up imaging is generally not required unless specific concerns arise
Long-term dietary modifications are usually not necessary unless specific bowel issues persist.
Key Points
Exam Focus:
Most common cause of SBO in developed nations is adhesions
History of prior abdominal surgery is the most important clue
CT abdomen/pelvis is the gold standard for diagnosis and complication detection
Open laparotomy is indicated for signs of ischemia/perforation or failed conservative management
Meticulous adhesiolysis is key to prevent iatrogenic injury.
Clinical Pearls:
Always suspect adhesions in a patient with SBO and a surgical scar
Differentiate partial from complete obstruction based on ability to pass flatus/stool
Early NG decompression is critical for symptomatic relief and fluid management
Be vigilant for signs of bowel compromise (tenderness, rigidity, fever, elevated lactate)
Thoroughly inspect the entire bowel during surgery to identify all obstructing adhesions.
Common Mistakes:
Delayed surgical intervention in cases of complete SBO or suspected ischemia
Insufficient resuscitation with fluids and electrolytes
Inadequate decompression with NG tube
Incomplete adhesiolysis leading to recurrent obstruction
Iatrogenic injury to the bowel during dissection
Overlooking signs of perforation or sepsis during initial assessment.