Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gen Surgery > Volvulus of the colon > Flashcards

Volvulus of the colon Flashcards

1
Q

What is a volvulus?

A

Condition where a loop of bowel and its mesentery twists on a fixed point at its base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What anatomical conditions must be present before volvulus can be produced

A

Long, mobile loop of bowel with close approximation of the points of attachment of its limbs which readily allows axial rotation to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the Mechanisms of progression to gangrene

A
  • Obstruction of mesenteric blood flow as a result of torsion and angulation
  • The second is venous and arterial obstruction when intraluminal pressure exceeds diastolic and then systolic blood pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What indicates an interference of blood supply in the bowel

A
  • Subserosal petechiae
  • Blood stained ascites
  • Gangrene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does massive sequestration of blood in the bowel lead to?

A

It produces grave forms of oligaemic hypotension leading to mortality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the most common sites for volvulus to occur

A
  • Most common site: Sigmoid colon
  • Caecum
  • Less common: transverse colon, splenic flexure and the descending colon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference in epidemiology in sporadic and endemic sigmoid volvulus

A
  • Endemic: Males predominate (90% of reported cases) and occurs in younger patients
  • Sporadic: less male preponderance or equal male to female ratio. Some series show institutionalised elderly female preponderance with a history of chronic constipation. Most common age at presentation is between 60- 70 years old.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the usual anatomical parameters necessary for sigmoid volvulus to occur

A

Sigmoid volvulus occurs in patients with a long sigmoid colon and mesocolon and narrow mesentery attachments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the proposed causes of sigmoid volvulus

A
  • Chronic constipation
  • Bowel habit
  • High fibre diet
  • use of enemas
  • Altitude
  • the inherent length of the sigmoid colon in certain population groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the pathological features in endemic sigmoid volvulus (External characteristics of the bowel)

A
  • Circular muscular coat is hypertrophied
  • Longitudinal coat is thinned out over the surface of the tubular megacolon
  • Taeniae coli are often quite broad and spread out
  • Appendices epiploicae may be absent and there is complete lack of normal haustrations
  • Blood supply to the colon is increased
  • In some cases, the base segements of bowel are only a few centimeters apart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is thought to be the cause of the thickening of the mesocolon in endemic sigmoid volvulus

A
  • It is thought to be due to recurrent torsion which may precede acute obstruction of the colon by many years and results in the limbs of the sigmoid being drawn closer by the shrinking mesentery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the most important secondary pathological effects of a volvulus where the megacolon extends below the site of torsion above the pelvic inlet

A

-Gross abdominal distension and fluid loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Typical history of sigmoid volvulus

A
  • Recurrent attacks of abdominal distension, constipation and pain culminating in the patient’s arrival at hospital
  • Pain is mild colicky type
  • The attack may end with the passage of flatus rather than faeces or history may reveal it was relieved by enema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the typical pain of gangrene of the loop or ileo-sigmoid knot

A

Pain which is an outstanding feature and which radiates to the back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Findings on physical exam in sigmoid volvulus

A
  • Abdominal distension is a striking feature (generalized but can be more marked on the left, on the right or centrally)
  • Little tenderness except in presence of gangrene
  • Abdomen tympanic on percussion
  • Possible to palpate the outline of the distended large intestine
  • Rectal examination reveals an empty rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Radiological features of sigmoid colon volvulus

A
  • Bent inner tube (formed by a gas shadow that is looped on itself)
  • The coffee bean sign
  • The summation line
  • A disproportionately distended sigmoid colon rising from the left iliac fossa towards the right hypochondrium which may elevate the diaphragm and overlap the liver outline can sometimes be seen
  • Walls of the volvulus appear smooth with no haustrations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Features of sigmoid colon volvulus in barium enema

A

-hooked beak appearance of the sigmoid obstruction with a twisted appearance to the mucosa is confirmatory

18
Q

When is barium enema contraindicated

A

patients with suspected colon infarction or perforation

19
Q

What sign is seen on CT in Sigmoid colon volvulus

A

CT ‘whirl’ sign caused by the twisted mesentery and the afferent and efferent limbs of the sigmoid colon

20
Q

Predisposing factors for sigmoid colon volvulus in children

A
  • Chronic colonic obstruction (eg Hirschprungs)

- Redundant sigmoid with elongated mesentery (most common cause)

21
Q

First choice treatment in patient with viable bowel?

A

Sigmoidoscopy

22
Q

What signifies that sigmoidoscopy has had a therapeutic benefit in a patient with sigmoid colon volvulus

A

Instant release of a large quantity of fluid faeces and flatus often in an explosive manner
-Dramatic subsidence of the abdominal distension

23
Q

Which site can the rigid sigmoidscope reach? What are the options if the site of torsion is above this?

A
  • It is able to reach 15 cm above the anal verge

- Where the twist is beyond this point, flexible sigmoidoscopy or colonoscopy can be used

24
Q

Disadvantages of sigmoidoscopy for sigmoid volvulus

A

-Reduction of gangrenous intestine and instrumental perforation

25
Q

Clinical signs of gangrene on sigmoidoscopy

A
  • Devitalised mucosa following reduction
  • Bloodstained effluent from the sigmoidoscope or rectal tube
  • presence of peritonitis
26
Q

contraindications to sigmoidoscopic decompression in sigmoid volvulus

A
  • Presence of gangrene

- Presence of compound volvulus

27
Q

Indications for urgent laparotomy in sigmoid volvulus

A
  • Failed attempt at decompression
  • Features suggestive of peritonitis
  • Presence of gangrene
28
Q

What surgical procedure is done for gangrenous colon in sigmoid volvulus

A

Resection followed by colostomy and Hartmann’s procedure

29
Q

What elective surgery is traditionally done for decompressed sigmoid volvulus

A

Resection of at least the sigmoid colon

30
Q

What non-resectional procedures are available for management of viable sigmoid colon after sigmoid volvulus

A
  • Colopexy: the redundant sigmoid colon is sutured into the anterior abdominal wall
  • Mesocoloplasty: one leaf of the long sigmoid mesocolon is incised longitudinally, two flaps raised and sutured transversely, broadening the attachment
31
Q

What are the anatomic prerequisites for the development of an ileo-sigmoid knot

A
  • Hyper mobile small intestine with unduly elongated mesentery having greater breadth and narrow base
  • Unusually redundant, omega-shaped sigmoid colon with a long mesocolon having a narrow base of attachment
32
Q

management of an ileo-sigmoid knot

A
  • Small and large bowel involved in the knot should be resected.
  • Resected small bowel should be followed by primary anastamosis regardless of viability of the bowel
  • Gangrenous large bowel may be followed by primary anastomosis or colostomy and Hartmann’s procedure
33
Q

What are the two groups of Caecal volvulus

A
  • Axial ileo-colic volvulus (90%)

- Caecal bascule

34
Q

What is the usual direction of an ileo colic volvulus

A

Torsion is usually in a counter-clockwise rotation in an oblique fashion, also displacing the ileum

35
Q

Which direction does the caecum rotate in caecal bascule

A

It rotates in a horizontal plane anteriorly upwards , with the obstruction at the point of folding

36
Q

Clinical presentation of volvulus of the caecum

A
  • Generalised abdominal pain
  • abdominal distension
  • Constipation or obstipation
  • Vomiting
37
Q

Radiograph features of caecal volvulus

A
  • Single fluid level may be seen in dilated caecum located anywhere in the abdomen
  • Distended small bowel loops are often present
  • Relative absence of gas in the distal colon
  • Coffee bean sign
  • CT whirl sign
38
Q

Differentials for caecal volvulus

A
  • Gastric dilatation
  • Sigmoid volvulus
  • Small intestinal volvulus
  • Colonic obstruction with a competent ileo-caecal valve
39
Q

management of caecal volvulus

A
  • Urgent surgery
  • Determination of viability of bowel at laparotomy
  • Nonviable bowel removed by right hemicolectomy and primary anastomosis/ ileostomy/ mucous fistula
  • Viable bowel: de-torsion followed by right hemicolectomy/ caecopexy/ caecostomy
40
Q

Treatment of transverse colon volvulus

A
  • viable bowel at laparotomy: de torsion with resection/ colopexy
  • Gangrene: resection is the only option (transverse colectomy and a left or right extended hemicolectomy

Gen Surgery (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions