Colonic volvulus: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:57

Colonic volvulus occurs when a redundant segment of the colon twists on its mesentery, causing a closed loop obstruction where the blood supply to the colon can become compromised.
Now, in this closed loop, gas and secretions continue to build up with nowhere to go. This worsens the distension of the segment, and can lead to ischemia, necrosis, and ultimately perforation.
Colonic volvulus accounts for about 10% of large bowel obstructions and is more common in the elderly or in patients with chronic constipation.
There are two major types of colonic volvulus depending on its anatomic location, which can involve the cecum or the sigmoid colon.
Regardless of the type, timely diagnosis and treatment is very important to prevent necrosis and perforation of the involved bowel segment.

Unstable patient0:57–4:48

When assessing patients with a chief concern suggesting colonic volvulus, your first step is to perform an ABCDE assessment to determine if the patient is stable or unstable.
If the patient is unstable, begin acute management immediately to stabilize the airway, breathing, and circulation. This means that you might need to intubate the patient, obtain IV access, administer fluids, and monitor vital signs.
Additionally, keep the patient NPO and place a nasogastric tube for small bowel decompression. Next, quickly obtain a focused history and physical examination, and order labs such as CBC, CMP, and lactate, as well as an abdominal x-ray.Okay, let’s discuss what you might find on history and physical examination.
The history will typically reveal an acute onset of crampy abdominal pain, obstipation or constipation, and bloating. As the passage through the colon is blocked, the content of the intestine will start backing up.
So over time, patients might develop nausea and vomiting as well. Be sure to ask about any previous episodes of colonic volvulus and what treatment they received at that time.
On physical exam, you might find altered mental status, tachycardia, and hypotension, which are signs of septic shock. Additionally, you can expect to see a distended tympanic abdomen with diffuse rebound tenderness with guarding.
Finally, you should perform a digital rectal exam to rule out an obstructing rectal mass. Now, let's talk about the lab results.
You might see leukocytosis on CBC, electrolyte imbalances on CMP, and an elevated lactate level indicating metabolic acidosis.
Alright, abdominal x-ray findings depend if you’re dealing with cecal or sigmoid volvulus. As the bowel segment twists around its mesentery, it actually moves to a different area of the abdomen.
So, cecal volvulus will be seen as a closed loop of bowel usually in the left upper quadrant. Since the blockage is at the very start of the large bowel, the small bowel might become distended, while distal areas of the large bowel are decompressed.
Finally, there is only one air-fluid level. On the flip side, sigmoid volvulus appears as a coffee bean sign.
This is when the twisted bowel segment resembles a coffee bean on imaging. It is typically found in the right upper quadrant.
Since the blockage is at the end of the large bowel, proximal areas of the large bowel might be distended, while the rectum appears decompressed.
There might also be multiple air-fluid levels.In both cases, you may possibly see pneumoperitoneum, or air under the diaphragm indicating bowel perforation.
If you see these findings, you should suspect colonic volvulus with peritonitis from bowel ischemia, necrosis or perforation, which are all surgical emergencies.
Here’s a high-yield fact! Coffee bean sign is known by many other names including the omega sign, bent inner tube sign, inverted U sign, or kidney bean sign.
So, don’t be confused if you hear any of these.Alright, the next step is to immediately begin supportive care and obtain surgical consultation for an emergent laparotomy.
Supportive care includes IV fluid resuscitation and consider vasopressor support if necessary, as well as electrolyte replacement, broad-spectrum IV antibiotics, and bowel rest.
Exploratory laparotomy in this case is both diagnostic and therapeutic, so nothing should delay patients from going to the operating room.Okay, now that unstable patients are treated, let's go back and talk about stable patients.

Stable patient4:48–7:05

Your first step in evaluating a stable patient is to obtain a focused history and physical exam, as well as labs like CBC, CMP, and lactate.
Stable patients typically report abdominal pain, bloating, obstipation or constipation, and sometimes nausea and vomiting.
Patients might also report history of chronic constipation, as well as previous episodes of volvulus. Keep in mind that a lot of these patients are elderly, so some of them might not be able to provide history due to other concomitant conditions like dementia.
On physical exam, you can expect to find a distended and tympanic abdomen that is tender on palpation. Sometimes, you might hear hyperactive bowel sounds.
As before, you should perform a digital rectal exam to rule out an obstructing rectal mass. Finally, labs might demonstrate leukocytosis, electrolyte imbalances, and elevated lactate causing metabolic acidosis.
Based on these findings, you should suspect large bowel obstruction likely from colonic volvulus. Before you continue with your diagnostic work up, you should start supportive care right away.
This includes IV fluid resuscitation, correction of acid-base and electrolyte imbalances, broad-spectrum IV antibiotics, and bowel rest with nasogastric tube placement for small bowel decompression.
Once supportive care has been started, your next step is to order imaging such as an abdominal x-ray series, CT scan of the abdomen and pelvis with PO, IV, and rectal contrast, or a water-soluble contrast enema.
Alright, time for a clinical pearl! When assessing intestines for dilation, keep the 3, 6, 9 rule in mind.
Normal diameter of the small bowel is 3 cm. For the large bowel, it is 6 cm, while for cecum, the normal diameter is 9 cm.
Anything above this is considered dilated.Now, let's talk about what you might see on imaging. On x-ray, you might see a closed loop of bowel usually in the left upper quadrant, with distended small bowel, and decompressed distal bowel.

Cecal volvulus7:05–8:35

Finally, there is only one air-fluid level. As for the CT scan, it might show closed loop bowel obstruction with the twisting of the cecum, and a whirl sign created by a tightly twisted mesentery along the axis of the volvulus.
In later stages of the volvulus, you may also see pneumatosis or portal venous gas indicating bowel necrosis.Lastly, the water-soluble contrast enema will show a bird beak sign in the cecum, which represents tapering of the colon at the site of the volvulus.
However, if there is concern for necrosis and perforation, do not give a contrast enema!Here's a clinical pearl! A cecal bascule is an uncommon type of cecal volvulus where the cecum folds forward instead of twisting around its axis.
This causes the cecum to appear as a dilated loop of bowel in the center of the abdomen.If you see any of these radiographic findings, you can confirm your diagnosis of a cecal volvulus.
Once you have made your diagnosis, call for an urgent surgical consultation, since the treatment of choice in this case is a right hemicolectomy.Next, let's talk about a different set of findings on imaging.

Sigmoid volvulus8:35–10:37

X-ray might reveal the coffee bean sign, usually in the right upper quadrant. You might also see dilated loops of proximal large bowel, an absence of air in the rectum, and multiple air-fluid levels.On CT scan, you can expect to see a closed loop obstruction with a twisted loop of the sigmoid colon.
Other CT findings include the whirl sign; as well as pneumatosis and portal venous gas in severe cases. Additionally, a water-soluble contrast enema will typically reveal a bird beak sign in the distal large bowel indicating a sigmoid volvulus.
Once again, if you see any of these radiographic findings, you can make your diagnosis of a sigmoid volvulus.Unlike cecal volvulus, your next step is to consult the surgical team for an urgent endoscopic decompression with a rectal tube placement.
Once the procedure has successfully detorsed the sigmoid, you need to assess for adequate response for several days. Although endoscopic decompression offers a less invasive method of treatment, there is a higher chance of recurrence.
If the patient shows signs of adequate response and resolution of the volvulus like clinical improvement of symptoms, you can refer the patient to the surgical team for an elective surgical intervention.
However, if the patient does not improve or the volvulus recurs, urgent surgical consultation is needed. Here’s one final clinical pearl!
In some cases, the contrast enema you did for diagnostic purposes can actually decompress the volvulus. If this happens, there is no need to do endoscopic decompression.
You can just continue with follow-up.Lastly, let's go back to imaging once more. If there are no signs of colonic volvulus, you can’t rule it out completely.

Consider alternative diagnosis10:37–11:02

That’s because it can be intermittent, so the patient might come back if it happens again. However, if there are signs of obstruction due to other causes, like a tumor, you should consider further workup for alternative diagnosis.Alright, as a quick recap… Patients with colonic volvulus may present as stable or unstable.
Unstable patients should be evaluated with an x-ray. Since they have signs of colonic volvulus with peritonitis from bowel necrosis or perforation, they should be taken to the operating room emergently for laparotomy, which is both diagnostic and therapeutic.

Review11:02–12:00

On the other hand, stable patients should undergo x-ray, CT scan of the abdomen and pelvis with contrast, and sometimes water soluble contrast enema to determine the anatomic location of the volvulus.
Cecal volvulus requires immediate surgical intervention like a right hemicolectomy, while sigmoid volvulus can be treated with endoscopic decompression before pursuing surgical intervention.
If, however, endoscopic decompression fails or volvulus recurs, an urgent surgical consultation is necessary for definitive treatment.
exhibit the volvulus can be treated with endoscopic decompression before pursuing surgical intervention If however endoscopic decompression fails or volvulus recurs an urgent surgical consultation is necessary for definitive treatment