Colorectal and general surgery Flashcards
Laparoscopy complications
general anaesthetic risks
Vasovagal reaction in response to abdo distension
Extra-peritoneal gas insufflation (surgical emphysema)
Injury to GI tract
Injury to blood vessels
Gastric MALT lymphoma
Associated with H pylori in 95% of cases
Good prognosis
Most respond to H pylori eradication
Paraproteinaemia may be present
Complications of gastrectomy
Dumping syndrome:
- Early: food of high osmotic potential moves into small intestine causing fluid shift
- Late: rebound hypoglycaemia. Surge of insulin following food of high glucose value in small intestine - 2-3hrs later the insulin overshoots causing hypoglycaemia
Weight loss Early satiety Iron deficiency anaemia Osteoporosis Osteomalacia Vit B12 deficiency Increased risk of gallstones Increased risk of gastric cancer
Abdominal stomas
Small bowel stomas should be spouted so that their irritant contents are no in contact with the skin
Types of stomas:
- Gastrostomy: in the epigastrium, used for feeding and gastric decompression or fixation
- Loop jejunostomy: any location, used following laparotomy with planned early closure
- Percutaneous jejunostomy: usually LUQ, usually performed for feeding
- Loop ileostomy: usually RIF, used following defunctioning of colon
- End ileostomy: usually RIF, usually following complete excision of colon or where ileocolic anatamosis is not planned
- End colostomy: either LIF or RIF, used when a colon diversion or resection is dont and anastamosis is not primarily achievable
- Loop colostomy: located anywhere, used to defunction a distal segment of colon
Anal cancers
- type
- borders of the anus
- lymphatic drainage
- risk factors
- clinical features
- Majority are squamous cell carcinomas
- The anus ranges from the anorectal junction to the anal margin
- Lymphatic drainage/tumour spread at the anal margin goes to the inguinal lymph nodes, and tumours at the anorectal junction spread to pelvic lymph nodes
- Risk factors: HPV, anal intercourse, immunosuppression, HIV, women with a history of cervical cancer or CIN, smoking, 1:2 (m:f)
- Clinical features: perianal pain, perianal bleeding, palpable lesion, faecal incontinence, rectovaginal fistula
- Ix: T stage assessment (exam, DRE, anoscopic exam with biopsy, palpation of inguinal nodes), CT, MRI, endo-anal US, PET, HIV test
Anal fissures
Longitudinal or elliptical tears of squamous lining of the distal anal canal
Acute if present for <6 weeks, chronic if present for ?6 weeks
Risk factors: constipation, IBD, STIs
Features: painful, bright red, rectal bleeding
90% occur on the posterior midline
Mx of acute fissure:
High fibre diet and high fluid intake, bulk-forming laxatives are first line, lubricants (petroleum jelly) before defaecation, topical anaesthetics, analgesia
Mx of chronic fissure:
All of the above, plus more. Topical GTN is first line, if topical GTN is not effective after 8 weeks then refer to secondary care (sphincterotomy or botox)
Causes of anorectal abscess
Positions of anorectal abscesses
Causes: E coli, Staphylococcus aureus
Positions: perianal, ischiorectal, pelvirectal, intersphincteric
Rectal prolapse
- risk factors
- two types
- presentation
- ix
- mx
RF: increasing age, female, multiparous, straining, anorexia, previous traumatic vaginal delivery
May be internal or external
External are at risk of ulceration and long term incontinence
Clinical features: rectal mucous discharge, faecal incontinence, PR bleed, visible ulceration
Full thickness: rectal fullness, tenesmus, repeated defaecation
Ix: colonoscopy, defaecating proctogram, anorectal manometry studies, examination under GA
Mx:
- acute: reduce the prolapse and cover with sugar to reduce swelling
- Delormes procedure (excise mucosa and plicate the rectum)
- Altmeirs procedure (resect the colon)
- Rectopexy (rectum is elevated and fixed at the level of the sacral promontory)
Location of colorectal cancers in order of how common they are
Rectal (40%) Sigmoid (30%) Ascending colon and caecum (15%) Transverse colon (10%) Descending colon (5%)
2 week wait referral criteria for colorectal cancer
Patients >=40 with unexplained weight loss and abdo pain
Patients >= 50 with unexplained rectal bleeding
Patients >= 60 with iron deficiency anaemia OR change in bowel habit
Or: anyone who shows occult blood in their faeces
Faecal occult blood testing (FOBT) and faecal immunochemical testing (FIT) screening programme
FIT is a type of FOBT which is sent through the post to the patient
Used to detect and quantify the amount of human blood in a single stool sample
Screening programme offered every 2 years to all men and women aged 60-74
Patients >74 may request screening
Patients with abnormal results are offered a colonoscopy
50% will be normal, 40% will have polyps which are removed, 10% will have cancer
Colorectal cancer management
- Following diagnosis, patients require a CT CAP for staging
- Their entire colon should also be evaluated with colonoscopy or CT colonography
- MDT discussion regarding treatment plan
- Treatment:
- Colonic cancer: resectional surgery is the only curative option. Stents, surgical bypass and diversion stomas as palliative adjuncts. The lymphatic chains are also removed. Once the affected colon is removed, there will either be an anastamosis formed or an end stoma. If at risk of disease recurrence, chemotherapy is offered afterwards.
-Rectal cancer: rectal tumours involving the sphincter complex or very low tumours on the anal verge require abdomino-perineal excision of the rectum. Upper and lower rectal tumours can have anterior resection. Rectal resections require a 2cm clearance margin, and meticulous dissection of mesorectal fat and lymph nodes (TME). Colo-rectal anastamosis can then occur.
Many patients are also offered neoadjuvant radiotherapy prior to resectional surgery. Patients with obstructing rectal cancers should have a defunctioning loop colostomy
Site of colorectal cancer - type of resection - anastamosis
Caecal, ascending or proximal transverse colon: right hemicolectomy: ileo-colic anastamosis
Distal transverse, descending colon: left hemi-colectomy: colo-colon anasatmosis
Sigmoid colon: high anterior resection: colo-rectal anastamosis
Upper rectum: anterior resection and TME: colo-rectal anastamosis
Lower rectum: anterior resection and low TME: colo-rectal anastamosis or defunctioning stoma
Anal verge: abdomino-perineal excision of rectum: no anastamosis required
Factors needed for an anastomosis to heal
In which situations would you construct an end stoma rather than attempting an anastomosis
Adequate blood supply
Mucosal apposition
No tissue tension
Sepsis, unstable patients, inexperienced surgeons -> end stoma rather than anastomosis
In an emergency setting where the bowel has perforated, the risk of an anastomosis is much greater (esp colon-colon) - an end colostomy is often safer and can be reversed later
What is Hartmann’s procedure
Used in emergency bowel surgery, eg. bowel obstruction or perforation
Resection of the rectosigmoid colon with formation of an end colostomy and closure of the anorectal stump
Dukes classification
Dukes A: tumour confined to mucosa (95% 5yr)
Dukes B: tumour invading bowel wall (80% 5yr)
Dukes C: lymph node metastases (65% 5yr)
Dukes D: distant mets (5% 5yr)
Genetics of inherited colorectal cancer syndromes
Familial adenomatous polyposis: more than 100 adenomatous polyps affecting the colon and rectum. APC gene. Autosomal dominant.
Gardner syndrome: same as FAP but with desmoid tumours and mandibular osteomas. APC gene
Hereditary non-polyposis colon cancer (Lynch syndrome): colorectal cancer without extensive polyposis. Endometrial cancer, renal and CNS cancers.
Diverticular disease
- what is it
- symptoms
- diagnosis
- complications
- treatment
Herniation of colonic mucosa through the muscular wall of the colon
Symptoms: altered bowel habit, bleeding, abdo pain
Diagnosis: colonoscopy, CT cologram or barium enema
In an acutely unwell surgical patient, they may also receive a plain AXR and CXR to exclude perforation, and an abdo CT with constrast to identify any acute inflammation and local complications
Complications: diverticulitis, haemorrhage, fistula, perforation and faecal peritonitis, perforation and development of abscess, development of diverticular phlegmon
Mx:
- Increase fibre
- Mild attacks may be managed with abx
- Peri colonic abscesses should be drained (surgically or radiologically)
- Recurrent episodes of acute diverticulitis requiring hospitalisation is an indication for a segmental resection
- Perforation with faecal peritonitis will require a resection and a stoma
- Less severe perforations may be managed with laparoscopic washout and drain insertion
Diverticulitis
- what is it
- risk factors
- presentation
- signs
- investigations
- management
Infection of a diverticulum (out-pouching of intestinal mucosa)
RF: age, lack of fibre, obesity, sedentary lifestyle, smoking, NSAID use
Presentation: severe LIF pain, N+V, constipation (50%) or diarrhoea (25%), urinary frequency/ urgency/ dysuria, PR bleeding
Pneumaturia or faecaluria if colovesical fistula
Vaginal passage of faeces or flatus if colovaginal fistula
Signs: low grade pyrexia, tachycardia, tender LIF (may have a palpable mass due to inflam or abscess), possibly reduced bowel sounds
If perforation -> guarding, rigidity, rebound tenderness
Lack of improvement with treatment -> ?abscess
Ix:
- FBC (raised WCC)
- CRP (raised)
- Erect CXR (pneumoperitoneum if perforation)
- AXR (dilated bowel loops, obstruction, or abscess)
- CT (best modality in suspected abscesses)
- Colonoscopy (avoid initially due to increased risk of perforation)
Mx:
- oral abx, liquid diet and analgesia in mild cases
- if symptoms dont settle in 72 hours or patient initially presents with severe symptoms -> IV abx
Haemorrhoids
- where are they found
- clinical features
- types
- grading of internal haemorrhoids
- management
Found in the left lateral, right posterior and right anterior portions of the anal canal (3 o clock, 7 o clock, 11 o clock)
Clinical features: painless rectal bleeding (bright red on the paper), pruritus, pain (usually not significant unless piles are thrombosed), soiling may occur with third or fourth degree piles
Types:
- external: originate below the dentate line, prone to thrombosis, may be painful
- internal: originate above the dentate line, do not generally cause pain
Grading of internal:
1: does not prolapse out of the anal canal
2: prolapse on defaecation but reduce spontaneously
3: manually reduced
4: cannot be reduced
Management:
- soften stools (increase fibre and fluid)
- topical local anaesthetics and steroids may relieve symptoms
- outpatient treatments: rubber band ligation is superior to injection sclerotherapy
- surgery is reserved for large symptomatic haemorrhoids which do not respond to outpatient treatments
Acutely thrombosed external haemorrhoids
- typical presentation
- examination findings
- management
Typically presents with significant pain
O/E: purple, oedematous, tender subcutaneous perianal mass
If patient presents within 72 hours then referral should be considered for excision
Otherwise, patients can usually be managed with stool softeners, ice packs and analgesia.
Symptoms settle within 10 days usually.
Perianal abscess
- what is it
- more common in who?
- features
- causes
- ix
- mx
Collection of pus within the subcut tissue of the anus that has tracked from the tissue surrounding the anal sphincter
More common in men, usually around 40 years
Features: anal pain worse on sitting, hardened tissue in the anal region, pus-like PR discharge, systemic infection if abscess is longstanding
Causes: usually E coli (gut flora). Those caused by Staph aureus are more likely to be a skin infection rather than originating from the GI tract
Ix:
- usually diagnosed through inspection and DRE
- if ?underlying cause -> colonoscopy and blood tests (cultures and inflam markers)
- transperineal ultrasound is the gold standard in imaging anorectal abscesses (rarely used, except for complicated abscesses)
Treatment:
- Surgical incision and drainage is first line, under local anaesthetic. Then pack the wound (or leave open -> heals in 3-4wks)
- Abx if systemic upset secondary to abscess
Types of anorectal abscesses and where they are found
Ischiorectal: found between obturator internus muscles and external anal sphincter
Supralevator abscesses: forms when infection tracks superiorly from peri-sphincteric area to above the levator ani
Intersphincteric: between the internal and external anal sphincters
Conditions associated with anorectal abscesses
- Underlying IBD (esp crohns)
- DM is a risk factor due to poor wound healing
- Underlying malignancy (due to risk of bowel perforation -> abscess formation)
Causes of rectal bleeding
Anal fissure Haemorrhoids Crohns disease Ulcerative colitis Rectal cancer Diverticulosis and diverticulitis
Anal fissure Haemorrhoids Crohns disease Ulcerative colitis Rectal cancer
For all of the above: type of bleeding, features in history, examination findings
Anal fissure: bright red PR bleed. Painful bleeding that occurs post-defaecation in small volumes, usually due to constipation. Usually seen in the midline posteriorly.
Haemorrhoids: bright red PR bleed. Post defaecation bleeding on toilet paper and in toilet pan. May be alteration of bowel habit and history of straining. No blood mixed with stool. No local pain. Normal colon and rectum. Proctoscopy may show internal haemorrhoids. Internal haemorrhoids are usually palpable.
Crohns disease: bright red or mixed blood. Bleeding that is accompanied by other symptoms (altered bowel habit, malaise, fissures, abscesses). Perianal inspection may show fissures or fistulae. Proctoscopy may demonstrate indurated mucosa and possible strictures. Skip lesions on colonoscopy.
Ulcerative colitis: bright red bleed often mixed with stool. Diarrhoea, weight loss, nocturnal incontinence, passage of mucous PR. Proctitis is most marked finding. Colonoscopy will chow continuous mucosal lesions.
Rectal cancer: bright red blood mixed volumes. Alteration of bowel habit, tenesmus, symptoms of metastatic disease. Usually obvious mucosal abnormality, lesions may be fixed or mobile depending on extent of disease. Surrounding mucosa often normal, although polyps may be present.
Investigations for PR bleeding
Bloods: FBC, U+E, LT, coag studies, G+S
(elevated serum urea:creatinine ratio suggests an upper GI bleed)
Stool cultures are useful to exclude infective causes
If haemodynamically stable: flexible sigmoidoscopy to exclude left-colonic pathology. If inconclusive -> full colonoscopy.
If haemodynamically unstable: emergency upper GI endoscopy, and colonoscopy
CT angiography can be used if colonoscopy non-diagnostic
If excessive pain or ?fissure -> exam under GA or LA
If malignancy: MRI of the rectum for local staging, and CT CAP for staging of distant disease
Indications for surgery in UC
- Disease that is requiring maximal therapy or prolonged courses of steroids (proctocolectomy)
- Dysplastic transformation fo the colonic epithelium with associated mass lesions (proctocolectomy)
- Emergency presentations of poorly controlled disease that fails to respond to medical therapy (sub-total colectomy with an end ileostomy)
- Emergency presentation of toxic megacolon or perforation
Types of surgeries for UC
Subtotal colectomy with end ileostomy: usually done as an emergency. colon is removed and ileum is brought out of the body and attached to stoma. Rectum may be left in situ, allowing a pouch to be created later on.
Pouch surgery: the rectum gets removed and the pouch is made from the ileum to connect to the anus (no need for a stoma bag)
Restorative proctocolectomy with ileo-anal pouch: requires two or three operations. usually done as an elective procedure. Removal of the whole colon, leaving rectum and anus in situ. Temporary ileostomy formed. Later on, the rectum is removed and a pouch is made using the ileum which is joined to the anus, and the ileostomy is removed.
Instead of having an ileo-anal pouch, some people choose to have a permanent end-ileostomy
Indications for surgery in crohns disease
complications such as fistulae, abscess formation and strictures
Surgery doesnt equate with cure in crohns but may produce substantial symptomatic improvement
Volvulus
Torsion of the colon around it’s mesenteric axis resulting in compromised blood flow and closed loop obstruction
Occurs in the sigmoid (80%) or caecum (20%)
Features: constipation, abdominal bloating, abdominal pain, N+V
Diagnosis: plain AXR
- sigmoid volvulus: large bowel obstruction (large, dilated loop of colon, often with air-fluid levels) + coffee bean sign
- Caecum volvulus: small bowel obstruction
Management:
- Sigmoid: rigid sigmoidoscopy with rectal tube insertion
- Caecal: right hemicolectomy
Risk factors of sigmoid volvulus
Risk factors of caecal volvulus
Sigmoid: older patients, chronic constipation, Chagas disease, neuro conditions (parkinsons, duchenne), psychiatric conditions (schizophrenia)
Caecal: can occur in all ages, adhesions, pregnancy
Risk factors for colorectal cancer
Majority are sporadic Increasing age Family history IBD Low fibre diet High processed meat intake Smoking High alcohol intake
Clinical features of bowel cancer
Change in bowel habit Rectal bleeding Weight loss Abdo pain Iron deficiency anaemia
Right-sided: abdo pain, occult bleeding, anaemia, mass in RIF, late presentation
Left-sided: rectal bleeding, change in bowel habit, tenesmus, LIF mass or mass on PR exam
Investigations for colorectal cancer
- Routine bloods: FBC (microcytic anaemia), LFTs, clotting
- Carcinoembryonic antigen tumour marker should not be used for diagnosis but can be used to monitor disease after diagnosis
-Imaging:
Gold standard is colonoscopy with biopsy
If colonoscopy not suitable, flexible sigmoidoscopy or CT colonography can be done
Following diagnosis -> staging:
- CT CAP for distant mets and local invasion
- MRI rectum for rectal cancer to assess local staging
- Endo-anal ultrasound for early rectal cancer
Causes of pseudo-obstruction
Electrolyte imbalance or endocrine disorders: hypercalcaemia, hypothyroidism, hypomagnesaemia
Medication: opioids, CCBs, antidepressants
Recent surgery, severe illness or trauma (inc cardiac ischaemia)
Neuro disease: parkinsons, MS, hirschsprungs disease
What is pseudo-obstruction?
Interruption of the autonomic nervous supply, resulting in the absence of smooth muscle action in the bowel wall
Untreated cases results in an increasing colonic diameter, leading to an increased risk of toxic megacolon, bowel ischaemia and perforation
Differential diagnoses for pseudo-obstruction
Mechanical bowel obstruction
Paralytic ileus
Toxic megacolon
Constipation
Investigations for pseudo-obstruction
Bloods:
- U+Es
- Calcium
- Magnesium
- TFTs
Imaging:
- AXR (bowel distension)
- CT abdo-pelvis with IV contrast (definitive diagnosis as it can exclude mechanical obstruction)
Management of pseudo-obstruction
Most cases can be managed conservatively
NBM
IV fluids and NG tube insertion (drip and suck)
If it doesnt resolve in 24-48hrs -> endoscopic decompression
If not responding -> segmental resection +/- anastomosis
Pilonidal sinus
- risk factors
- clinical features
RF: caucasian males with coarse dark body hair, associated with those who sit for prolonged periods, increased sweating, buttock friction, obesity, poor hygiene, local trauma
Clinical features: intermittent red, painful and swollen mass in the sacrococcygeal region.
Discharge from the sinus. May have systemic features of infection
Distinguishing features compared to a perianal fistula is that a pilonideal sinus opens up into the skin but does not communicate with the anal canal (perianal fistula can open up into the skin but does communicated with anal canal)
pathophysiology of pilonidal sinus
Starts from a hair follicle in the intergluteal cleft becoming infected or inflamed
The inflammation obstructs the opening of the follicle, which extends inwards, forming a pit
A foreign body type reaction may then lead to formation of a cavity, connected to the surface of the skin by an epithelialised sinus tract
Management of pilonideal management
-Conservative: shave the affected area, pluck embedded hairs, wash out any accessible sinuses, abx if septic
Surgical:
- Abscess: incision and drainage with washout
- Chronic disease: removal of the pilonidal sinus tract
Angiodysplasia
- what is it
- clinical features
- Ix
Most common vascular abnormality of the GI tract
Caused by formation of arteriovenous malformations
Common in the caecum and ascending colon
Clinical features: rectal bleeding and anaemia are most common features.
- asymptomatic
- painless occult PR bleeding
- acute haemorrhage (upper GI -> haematemesis or malaena, whereas lower GI -> passage of fresh blood from anus)
Ix:
- Bloods (FBC, U+E, LFTs, clotting, ?G+S, ?crossmatch)
- Imaging: upper GI endoscopy and/or colonoscopy if occult angiodyspasia. Small bowel bleeds are harder to identify and requires wireless capsule andoscopy. Mesenteric angiography in overt angiodysplasia
Management of angiodysplasia
10% present with major GI bleed -> treat accordingly
If minimal bleeding and haemodynamically stable -> treat conservatively
Conservative treatment: bed-rest, IV fluids, tranexamic acid
If persistent or severe:
- Endoscopy: usually first line. Most widely used technique is argon plasma coagulation
- Mesenteric angiography: used for small bowel lesions that cannot be treated endoscopically (super selective catheterisation and embolisation of the vessel)
Surgical management: resection and anastamosis of affected bowel. Associated with high mortality so only dont if absolutely necessary
Indications for bowel resection in angiodysplasia
Continuation of severe bleeding despite treatment
Severe acute life-threatening GI bleeding
Multiple angiodysplastic lesions
Complications of angiodysplasia
Complications are mainly related to the treatment
Re-bleeding post-therapy is common
Endoscopic techniques has a small risk of bowel perforation
Mesenteric angiography carries risks of haematoma formation, arterial dissection, thrombosis and bowel ischaemia
Gastroenteritis
- risk factors
- infective causes
- non infective causes
- clinical features
- investigations
- management
RF: poor food prep, immunocompromised, poor personal hygiene
Infective causes:
- Viruses: norovirus, rotavirus, adenovirus
- Bacteria: campylobacter, E coli, Salmonella, Shigella
- Bacterial toxins: Staph aureus, Bacillus cereus, Clostridium perfringes
- Parasites: cryptosporidium, Entamoeba histolytica, giardia intestinalis, Schistoma
- Hospital acquired: Clostridium difficile
Non-infective causes:
- radiation colitis
- IBD
- Microscopic colitis
- Chronic ischaemic colitis
Clinical features:
- Cramping abdo pain
- Diarrhoea (+/- blood or mucus)
- Vomiting
- Pyrexia
- Dehydration
Ask about bowel movements, any affected friends or family, recent travel, recent use of antibiotics
Ix: not necessary as self limiting
-Stool culture often done, especially if blood or mucus in stool, if patient is immunocompromised or if severe/persistent
Mx:
- Rehydration (encourage oral fluid intake where possible, consider admitting for IV fluids)
- Education to prevent future episodes
- Exclusion from work for 48 hours form last episode of D+V
- Food poisoning and infectious bloody diarrhoea are notifiable diseases
- Campylobacter and salmonella are notifiable organisms
Epigastric hernia
- where does it occur
- why does it occur
- who does it occur in
- what are the symptoms
- what is a differential to exclude
Occurs in the upper midline through the fibres of the linea alba
Secondary to chronically raised intra-abdominal pressure (obesity, pregnancy, ascites)
Most common in middle-aged men
Typically asymptomatic, may present as a midline mass that disappears when lying down
Differential: divarication of the recti
Paraumbilical hernia
- where does it occur
- why does it occur
- how does it present
Herniation through the linea alba around the umbilical region (not through the umbilicus itself)
Typically secondary to chronic raised IAP
Presents as a lump around the umbilical region
Generally contain pre-peritoneal fat, although sometimes contain bowelO
Obturator hernia
- where does it occur
- who does it occur in
- how does it present
- sign elicited if obturator nerve is compressed
Hernia of the pelvic floor, through the obturator foramen into the obturator canal
More common in women (wider pelvis), typically in elderly patients
Present: mass in upper medial thigh, often patients will have features of small bowel obstruction
About 50% of causes causes compression of the obturator nerve -> positive Howship-Romberg sign (hip and knee pain exacerbated by thigh extension, medial rotation and abduction)
