Sabiston Obstruction Flashcards
(23 cards)
Adult colonic intussusceptions
in contrast to pediatric intussusceptions, are almost always associated with a pathologic lead point, such as a polyp, cancer, Meckel, or colonic diverticulum.
A recent meta-analysis found malignancy as the causative factor in 36.9% of ileocolonic and 46.5% of colonic intussusceptions.
Most authors recommend surgical resection adhering to oncologic principles without reduction
Patients with malignant obstruction of the low and mid rectum
usually require an initial diverting stoma to allow for neoadjuvant chemoradiation prior to definitive surgery.
Malignant obstructions of the sigmoid and left colon without signs of impending perforation
can be treated with initial endoscopic stenting as a bridge to surgery, or initial surgery.
Surgical options include segmental resection with Hartmann operation (end colostomy with internal closure of the rectal stump) or primary anastomosis with or without a diverting stoma
If the cecum is ischemic or nonviable
a subtotal colectomy is performed
right-sided obstruction
In cases of right-sided obstruction
a right hemicolectomy is typically performed with primary anastomosis.
Patients who are unstable with a high risk for anastomotic failure
should undergo creation of a temporary diverting stoma or exteriorization of the anastomosis as a loop ileostomy.
In patients with sigmoid volvulus
endoscopic decompression is often successful using either a rigid or flexible sigmoidoscope with placement of a rectal tube proximal to the point of torsion.
If this is unsuccessful, patients require surgery with resection, colostomy, and a Hartmann procedure.
If decompression is successful, elective sigmoid resection with primary anastomosis
With cecal volvulus
primary resection and anastomosis can typically be performed unless the patient is at increased risk of anastomotic leak (e.g., nonviable bowel, sepsis, hypotension, etc.).
obstruction as a result of active IBD
will commonly respond initially to steroids.
Paracolic abscesses
can be drained percutaneously
Foreign bodies
can usually be removed endoscopically.
Fecal impaction
is commonly relieved with a combination of stool softeners and laxatives from above and manual disimpaction at the bedside or in the operating room under anesthesia.
Hernias causing mechanical large bowel obstruction
usually require surgery
Conditions associated with pseudo-obstruction
see
suspicion of pseudo-obstruction xray
Dilation and gas continuing all the way down to the distal rectum support the suspicion of pseudo-obstruction in contrast to a mechanical obstruction in which a paucity of gas is commonly encountered distal to the obstruction.
signs that may be indicative of colon ischemia, perforation, or impending perforation.
Abdominal tenderness, leukocytosis, fever, and cecal dilation more than 12 cm
When to Consider Nonoperative
supportive care is initiated for patients with a cecal diameter that is less than 12 cm without evidence of ischemia or perforation.
In cases that do not improve with supportive care or with a cecal diameter of more than 12 cm
without systemic toxicity and abdominal tenderness, colonic decompression is indicated
Neostigmine
given as a 2 to 2.5 mg IV bolus injected over 3 to 5 minutes and results in significant parasympathetic stimulation causing strong colonic peristalsis that usually leads to subsequent flatus and bowel movements.
> safe and effective option for patients with acute colonic pseudo-obstruction who have failed conservative management.
some patients requiring multiple drug administrations.
Neostigmine is contraindicated in
mechanical bowel obstruction and in patients with signs of ischemia or perforation.
It should be used with caution among patients with asthma, chronic obstructive lung disease, bradycardia, and recent acute coronary syndrome and in those with renal failure.
Neostigmine should be given in a monitored setting with atropine immediately available
Colonoscopic decompression
should be considered in patients with contraindications to neostigmine or for those who are unresponsive to it.
The aim of endoscopic decompression is to advance the scope to the right colon with minimal insufflation and use of narcotics and place a colonic decompression tube while removing as much gas as possible from the colon
Colonoscopic perforation rates following decompression
for pseudo-obstruction are in the range of 1% to 3%
Patients who do not respond to other lines of treatment or those who demonstrate signs of systemic toxicity, ischemia, or perforation require surgery.
Surgical options are determined according to the condition of the colon and the patient.
If the colon is viable, tube cecostomy or cecostomy can be performed, with high rates of success.
For patients with signs of ischemia or perforation, a resection, usually with a diverting stoma, is recommended.
