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Volvulus
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Hospital Surgery
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- 06 July 2010
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- 16 February 2009, pp 241-246
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Summary
This important condition has a significant morbidity and mortality and therefore requires a high index of suspicion. It can be missed as it often presents in the elderly and infirm.
Definition and classification
Volvulus is a rotation of a segment of bowel about its longitudinal mesenteric axis, resulting in occlusion of the proximal section. It most commonly affects the colon (the sigmoid and caecum) although small bowel (usually the lower ileum) or stomach may also be affected. It can be classified as primary (i.e. caused by congenital intestinal malrotation, abnormal mesenteric attachments or congenital ‘Ladd's’ bands), or secondary (more common), and can be either acute or chronic.
Incidence
Sigmoid volvulus is the most common type and is responsible for approximately 8% of all intestinal obstructions. Men are more commonly affected than women, most commonly in the sixth decade of life. Caecal volvulus is more common in women.
Aetiology
Associated with increasing age, chronic constipation, a high-roughage diet, lead poisoning, neurological conditions (e.g. Parkinson's disease), Surgical emergencies Hirschsprung's disease, patients in nursing homes and mental health facilities. Can be caused by round-worm infection and Chagas disease. Incomplete midgut rotation predisposes to caecal volvulus.
Pathology
Macroscopic: volvulus occurs secondary to a narrow mesentery in association with a long redundant sigmoid allowing two segments of bowel to come together and twist around the axis, usually anticlockwise in the case of the sigmoid volvulus, varying from 180° (35%) to 540° (10%) (Figure 43). Caecal volvulus usually involves clockwise axial rotation of terminal ileum, caecum and ascending colon around ileocolic vessels and mesentery (Figure 44). Microscopic: venous congestion andarterial compromise cause ischaemia and infarction.
Colorectal disease: colonic diverticular disease
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Book:
- Hospital Surgery
- Published online:
- 06 July 2010
- Print publication:
- 16 February 2009, pp 429-434
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Summary
Introduction: Diverticular disease is one of the commonest surgical conditions affecting theWesternWorld, and the burden of this disease is therefore increasing with the rising numbers in the elderly population. In most patients it remains asymptomatic but its potential complications have a high morbidity and mortality rate.
Definition and classification
A false pulsion diverticulum. Large bowel mucosa is forced through the muscularis propria where it is pierced by the vasa recta (Figure 93). Diverticulosis implies asymptomatic disease whereas diverticulitis is symptomatic. Diverticular disease can be classified as acute or chronic and complicated or uncomplicated.
Incidence
Diverticulosis affects about 50% of 60-year-olds. Increased incidence with age. F > M. It is predominantly a disease of the western World, probably related to dietary factors (but low incidence in western vegetarians).
Aetiology
This is predominantly an acquired disease. Commonest in the sigmoid colon. Its principle causes are thought to be a raised intraluminal pressure secondary to a poor diet causing bulky stools and colonic segmentation: tonic and rhythmic contractions result in non-propulsive contractions, producing isolated segments with high intraluminal pressure. A prolonged colonic transit time is also responsible.
Pathology
Macro: usually multiple and most frequent in sigmoid colon, right-sided diverticula are rare, and are usually seen in young Asian populations. Often associated with colonic structural changes e.g. elastosis of taenia coli, muscular hypertrophy, mucosal folding. Diverticula can cause (1) Fistulae: to bladder/vagina/small bowel/skin. (2) Perforation: 4/100 000 people with diverticular disease; 2000 cases/year. Most common at first presentation. (3) Abscess formation: pericolic or peritonitis.
Colorectal disease: colorectal cancer
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Book:
- Hospital Surgery
- Published online:
- 06 July 2010
- Print publication:
- 16 February 2009, pp 424-428
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Summary
Incidence
Second commonest cause of cancer deaths in both sexes after lung. 30 000 new cases per year in the UK. Increasing incidence with age, > 75 yrs = 300/100 000. Increasing incidence in UK. Colon M = F, rectal M > F, More common in developed countries. Incidence increasing in less-developed nations.
Aetiology
Family history: if one first-degree relative, the risk is increased more than two-fold. Two first-degree relatives or one first-degree relative diagnosed < 45 yrs indicates a lifetime risk of death from colorectal cancer of 1 in 6, or 1 in 10, respectively. 5% of colorectal-cancer patients have a genetic syndrome. Familial adenomatous polyposis (FAP) is an autosomal dominant mutation of the APC gene and presents with multiple colonic polyps. Hereditary non-polyposis coli (HNPCC) and Gardner's syndrome are also responsible.
Inflammatory bowel disease: ulcerative colitis for over 10 years gives an eight-fold age-related risk.
Lifestyle – increased risk with: obesity; smoking; diet – high in processed meats, low in vegetables and fibre, alcohol; reduced exercise; bile salts. Reduced risk with: folic acid, Ca2+, selenium, NSAIDs (including aspirin), HRT.
Pathogenesis
Two-thirds of cancers develop in the colon, the rest in the rectum. Adenomatous polyps have malignant potential via adenoma-carcinoma sequence: have tubular (70%), villous (10%), tubulovillous (20%) morphology. Left-sided cancers tend to be annular, stenosing and more likely to obstruct. Right-sided cancers are sessile and cause occult bleeding. 3% of tumours synchronous, 5–10% metanchronous. Majority are adenocarcinomas. Others: carcinoid, lymphoma, sarcoma. Cancers are graded as well, moderately or poorly differentiated.