24- Colyrectal Explains Flashcards
What imaging modalities are used for complete staging of colorectal cancer?
CT of the chest, abdomen, and pelvis; colonoscopy or CT colonography; MRI for evaluating the mesorectum in tumors below the peritoneal reflection
What is the main treatment for colon cancer?
Resectional surgery
What are some palliative adjuncts used in the treatment of colon cancer?
Stents, surgical bypass, and diversion stomas
How are colon resections tailored to the patient and tumor location?
Based on the lymphatic drainage, resecting specific lymphatic chains
What factors may influence the choice of procedure for colon cancer treatment?
Confounding factors like HNPCC family history, which may indicate a panproctocolectomy instead of segmental resection
What are the key technical factors for successful healing of an anastomosis after colon resection?
Adequate blood supply, mucosal apposition, and no tissue tension
When is it safer to construct an end stoma instead of attempting an anastomosis after colon resection?
In the presence of surrounding sepsis, unstable patients, or inexperienced surgeons
What are the options for a colonic cancer presenting with an obstructing lesion?
Stenting or resection
What is the common approach for defunctioning a colonic tumor with a proximal loop stoma?
Unusual in modern practice
What treatment is usually offered to patients with risk factors for disease recurrence after colon cancer resection?
Chemotherapy, commonly a combination of 5FU and oxaliplatin
How is rectal cancer management different from colonic cancer?
Due to the rectum’s anatomical location and challenges, rectal tumors can be surgically resected with either an anterior resection or an abdomino-perineal resection (APER)
What determines the choice between anterior resection and APER in rectal cancer surgery?
Involvement of the sphincter complex or very low tumors
What is the required distal clearance margin in rectal cancer surgery?
2 cm
Why is neoadjuvant radiotherapy offered more frequently in rectal cancer compared to colonic cancer?
Because the rectum can be irradiated, unlike colonic tumors
What is the crucial aspect of rectal cancer surgery in addition to rectal tube excision?
Meticulous dissection of the mesorectal fat and lymph nodes (total mesorectal excision/TME)
Which patients with rectal cancer do not require irradiation and can proceed straight to surgery?
Patients with T1, T2, and T3/N0 disease on imaging
What type of radiotherapy is typically offered to patients with T4 rectal cancer?
Long course chemo radiotherapy
What is the recommended treatment approach for obstructing rectal cancer?
Defunctioning loop colostomy, followed by staging and planning for resectional surgery
Summary of cancer resections:
Site of cancer Type of resection Anastomosis Risk of leak
Right colon Right hemicolectomy Ileo-colic Low (<5%)
Transverse colon Extended right hemicolectomy Ileo-colic Low (<5%)
Splenic flexure Extended right hemicolectomy Ileo-colic Low (<5%)
Left colon Left hemicolectomy Colo-colon 2-5%
Sigmoid colon High anterior resection Colo-rectal 5%
Upper rectum Anterior resection (TME) Colo-rectal 5%
Low rectum Anterior resection (Low TME) Colo-rectal (+/- Defunctioning stoma) 10%
Anal verge Abdomino-perineal excision of colon and rectum None n/a
What is the follow-up plan for LNPCP with R1 or non-en bloc resection?
Site check at 2-6 months, then further scope at 12 months
Colonic polyps:What is the risk of malignancy associated with adenomas?
Around 10% in a 1cm adenoma
Colonic polyps:What symptoms can distally sited villous lesions cause?
They may produce mucous and, if very large, electrolyte disturbances may occur
What is the recommended colonoscopy schedule after resection of colorectal cancer?
One year post-resection
What is the follow-up recommendation for large non-pedunculated colorectal polyps (LNPCP) with R0 resection?
One-time scope at 3 years
What is the surveillance recommendation for high-risk findings at baseline colonoscopy?
One-time surveillance at 3 years
What is the surveillance recommendation for no high-risk findings at baseline colonoscopy?
No colonoscopic surveillance, but invite participation in NHSBCSP program when due
What are the criteria for considering segmental resection or complete colectomy?
Incomplete excision of malignant polyp, malignant sessile polyp, malignant pedunculated polyp with submucosal invasion, polyps with poorly differentiated carcinoma, or familial polyposis coli
What should be considered if a patient is more than 10 years younger than the lower screening age and has polyps but no high-risk findings?
Colonoscopy at 5 or 10 years
What treatment option may be suitable for rectal polypoidal lesions?
Trans anal endoscopic microsurgery
Laxatives
Laxatives:
Bulk forming laxatives:
Bran
Psyllium
Methylcellulose
Osmotic laxatives:
Magnesium sulphate
Magnesium citrate
Sodium phosphate
Sodium sulphate
Potassium sodium tartrate
Polyethylene glycol
Stimulant laxatives:
Bisacodyl
Sodium picosulphate
Senna
Ricinoleic acid
Benign Proctology:
Fissure in ano:
Features: Painful, bright red rectal bleeding
Treatment: Stool softeners, topical diltiazem or GTN, botulinum toxin, sphincterotomy
Haemorrhoids:
Features: Painless, bright red rectal bleeding occurs following defecation and bleeds onto the toilet paper and into the toilet pan
Treatment: Stool softeners, avoiding straining, surgery if necessary
Fistula in ano:
Features: May initially present with an abscess and then persisting discharge onto the perineum, separate from the anus
Treatment: Lay open if low and no sphincter involvement or IBD, if complex, high, or IBD, insert a seton and consider other options
Peri-anal abscess:
Features: Peri-anal swelling and surrounding erythema
Treatment: Incision and drainage, leaving the cavity open to heal by secondary intention
Pruritus ani:
Features: Peri-anal itching, occasional mild bleeding (if severe skin damage)
Treatment: Avoid scented products, use wet wipes rather than tissue, avoid scratching, ensure no underlying faecal incontinence
What is the usual approach for treating haemorrhoids?
Conservative treatment
How can acute thrombosed haemorrhoids be managed?
Stool softeners, ice compressions, and topical GTN or diltiazem
What are the potential surgical options for residual haemorrhoids after conservative treatment?
Surgical excision of skin tags or haemorrhoidectomy
What procedure is beneficial for internal haemorrhoids with marked symptoms of bleeding and occasional prolapse?
Stapled haemorrhoidopexy
What are the adverse effects of stapled haemorrhoidopexy?
Urgency (settles over time) and recurrence
Which surgical procedure is suitable for large haemorrhoids with a substantial external component?
Milligan Morgan style conventional haemorrhoidectomy
What medication is commonly prescribed postoperatively to decrease pain after a haemorrhoidectomy?
Metronidazole
What is the most efficient and definitive treatment for fissure in ano?
Lateral internal sphincterotomy
What is a potential concern when using lateral internal sphincterotomy in females?
Faecal incontinence due to pregnancy and pelvic floor damage
What is the usual first-line therapy for fissure in ano?
Relaxation of the internal sphincter with either GTN or diltiazem (better tolerated) applied topically
What is the next treatment option for fissure in ano if topical therapy fails?
Treatment with botulinum toxin
Where do typical fissures usually present?
In the posterior midline
What treatment option is available for refractory cases of fissure in ano?
Advancement flaps
What is the most effective treatment for fistula in ano?
Laying it open (fistulotomy)
What imaging methods can be used to assess fistula in ano?
MRI or endoanal USS
When is laying fistula in ano open a reasonable option for treatment?
When the fistula is below the sphincter and uncomplicated
What is the recommended management for fistulas associated with Crohn’s disease?
Long-term placement of a draining seton suture and medical management
What are the generally unsuccessful treatment options for fistula in ano not associated with inflammatory bowel disease?
Instillation of plugs and glue
What is a newer technique for the management of fistula in ano?
Ligation of intersphincteric tract (LIFT procedure)
Ulcerative colitis Vs Crohns
Crohn’s Disease:
Distribution: Mouth to anus
Macroscopic changes: Cobblestone appearance, apthoid ulceration
Depth of disease: Transmural inflammation
Distribution pattern: Patchy
Histological features: Granulomas (non-caseating epithelioid cell aggregates with Langerhans’ giant cells)
Ulcerative Colitis:
Distribution: Limited to the rectum and colon
Macroscopic changes: Contact bleeding
Depth of disease: Superficial inflammation
Distribution pattern: Continuous
Histological features: Crypt abscesses, Inflammatory cells in the lamina propria
What is the main surgical treatment for ulcerative colitis?
Pan proctocolectomy
When is surgery typically performed in ulcerative colitis?
When medical treatment has failed
What surgical procedure is performed in the emergency setting for ulcerative colitis?
Subtotal colectomy, end ileostomy, and mucous fistula
What is an elective surgical option for ulcerative colitis?
Ileoanal pouch (selected option for some)
What should be considered in patients with longstanding ulcerative colitis?
Increased risk of colorectal cancer
What is the approach to surgical treatment in Crohn’s disease?
Minimal resections
What surgical option should Crohn’s patients avoid?
Ileoanal pouches
How is management of Crohn’s ano rectal sepsis typically approached?
Minimal approach, drainage of sepsis, and use of setons for facilitation of drainage
What type of surgery should be avoided in Crohn’s fistulas?
Definitive fistula surgery
What is the most common form of ano rectal sepsis?
Fistula in ano
What are the characteristics of fistulae?
They have both an internal opening and external opening connected by tract(s)
How are fistulae classified?
Into four main groups based on anatomical location and degree of sphincter involvement
What are the characteristics of simple uncomplicated fistulae?
They are low and do not involve more than 30% of the external sphincter
What are the characteristics of complex fistulae?
They involve the sphincter, have multiple branches, or are non-cryptoglandular in origin
What should be assessed during examination for fistulae?
Signs of trauma, external openings, stigmata of IBD, and the cord linking the internal and external openings
What imaging techniques are useful for assessing fistula anatomy?
Endo-anal USS with instillation of hydrogen peroxide and ano-rectal MRI scanning
What is the purpose of identifying the internal opening of a fistula?
To determine the course of treatment based on its location
What is Goodsall’s rule?
Fistulas with an external opening less than 3cm from the anal verge typically follow a specific pattern
What is a seton suture used for in anal fistula treatment?
A seton suture is used to allow the drainage of sepsis in complex anal fistulas.
Why is it important to drain sepsis in anal fistulas?
Undrained septic foci can lead to the development of additional tracts and openings.
What are the two types of seton sutures used in anal fistula treatment?
The two types of seton sutures used are simple setons and cutting setons.
What is the purpose of a simple seton suture?
A simple seton suture is placed within the fistula tract to promote drainage and fibrosis.
How does a cutting seton suture differ from a simple seton suture?
A cutting seton suture involves incising the skin and periodically tightening the suture. This technique aims to convert a high fistula to a low fistula.
What is the potential drawback of using cutting seton sutures?
Based on a large retrospective review, cutting seton sutures are associated with a long-term incontinence rate of 12%.
When is fistulotomy used as a treatment for anal fistulas?
Fistulotomy is used for low, uncomplicated fistulas once the acute sepsis has been controlled.
Why is fistulotomy considered to have a high cure rate?
Fistulotomy provides the highest healing rates among the treatment options.
What is the approach for more extensive sphincter involvement during fistulotomy?
In cases with more extensive sphincter involvement, the fistulotomy is performed as for a low fistula, but the muscle encountered is divided and reconstructed with an overlapping sphincter repair.
What is the potential consequence of performing fistulotomy with extensive sphincter involvement?
Performing fistulotomy with extensive sphincter involvement can result in issues with continence post-procedure for up to 12.5% of patients.
What were the outcomes of a study comparing fistulotomy, sphincter reconstruction, and ano-rectal advancement flaps?
The study reported similar outcomes in terms of recurrence (>90%) and disturbances to continence (20%) for the treatment of complex cryptoglandular fistulas.
What factors may increase the risk of adverse outcomes following fistulotomy?
Previous surgery, female gender, and high internal openings are factors that may increase the risk of adverse outcomes following fistulotomy.
What are surgeons using to improve healing of anal fistulas while avoiding sphincter injury?
Surgeons are using both fibrin glue and plugs to try and improve fistula healing while avoiding sphincter injury.
What should be considered prior to performing fistulotomy in patients with these risk factors?
In patients with these risk factors, careful assessment of pre-operative sphincter function should be considered mandatory prior to fistulotomy.
What is recommended prior to using anal fistula plugs or fibrin glue?
Meticulous preparation of the tract and prior use of a draining seton is recommended to improve the chances of success.
Why is the use of anal fistula plugs discouraged in high transphincteric fistulas?
The use of anal fistula plugs in high transphincteric fistulas is discouraged due to the high incidence of non-response in patients treated with such devices.
What are the reasons for failure in patients treated with anal fistula plugs?
In most patients, septic complications are the reasons for failure in patients treated with anal fistula plugs.
What is the reported variability of healing rates with fibrin glue for fistula treatment?
There is variability in reported healing rates with fibrin glue. Initial success rates of up to 50% healing at six months have been reported, but 25% of these successes experience long-term recurrence of the fistula.
What is ano-rectal advancement flaps primarily used for?
Ano-rectal advancement flaps are primarily used for high fistulas as a sphincter-saving operation.
What is the success rate of advancement flaps in treating cryptoglandular fistulas?
Follow-up studies show a success rate of up to 80% in patients with cryptoglandular fistulas treated with advancement flaps.
What is a potential complication of advancement flap surgery?
Continence may be affected in some patients, with up to 10% experiencing major continence issues post-operatively.
What is the ligation of the intersphincteric tract procedure?
In the ligation of the intersphincteric tract procedure, an incision is made in the intersphincteric groove, and the fistula tract is dissected and divided in this plane.
What is the reported cure rate of the ligation of the intersphincteric tract procedure?
The ligation of the intersphincteric tract procedure initially reported a greater than 90% cure rate within 4 weeks. Similar success rates have been observed in subsequent studies.
What does the Cochrane review suggest about primary fistulotomy for low, uncomplicated fistulas?
The Cochrane review suggests that primary fistulotomy for low, uncomplicated fistulas may be safe and associated with better outcomes in relation to long-term chronic sepsis.
What is the traditional teaching regarding primary treatment of acute sepsis in relation to fistulotomy?
The traditional teaching is that primary treatment of acute sepsis should be incision and drainage only, and high/complex fistulas should never be subject to primary fistulotomy in the acute setting.
What can the color of the blood indicate in terms of the bleeding source?
Bright red blood is usually of rectal anal canal origin, while dark red blood suggests a proximally sited bleeding source. Blood that has entered the GI tract from a gastro-duodenal source will typically resemble melaena due to the effects of digestive enzymes on the blood itself.
What are the features of rectal bleeding from a fissure in ano?
Rectal bleeding from a fissure in ano is bright red and occurs post-defecation in small volumes. It is usually accompanied by antecedent features of constipation.
What is a common cause for patients to be referred to the surgical clinic?
Rectal bleeding is a common cause for patients to be referred to the surgical clinic.
What are the features of rectal bleeding from haemorrhoids?
Rectal bleeding from haemorrhoids is bright red and is noted both on toilet paper and when it drips into the pan. There may be an alteration in bowel habit and a history of straining. No blood is mixed with the stool, and there is no local pain.
What are the examination findings for a fissure in ano?
A muco-epithelial defect is usually present, typically in the midline posteriorly (anterior fissures are more likely to be due to underlying disease).
What are the examination findings for rectal bleeding in ulcerative colitis?
Proctitis is the most marked finding. Perianal disease is usually absent. Colonoscopy will show a continuous mucosal lesion.
What are the features of rectal bleeding in Crohn’s disease?
Rectal bleeding in Crohn’s disease can be bright red or mixed blood. It is often accompanied by other symptoms such as altered bowel habit, malaise, and a history of fissures and abscesses.
What are the examination findings for haemorrhoids?
The colon and rectum are normal. Proctoscopy may show internal haemorrhoids, which are usually impalpable.
What are the examination findings for rectal bleeding in Crohn’s disease?
Perineal inspection may show fissures or fistulae. Proctoscopy may demonstrate indurated mucosa and possibly strictures. Skip lesions may be noted at colonoscopy.
What are the features of rectal bleeding in ulcerative colitis?
Rectal bleeding in ulcerative colitis is bright red and is often mixed with stool. Other symptoms may include diarrhea, weight loss, nocturnal incontinence, and the passage of mucous per rectum.
What are the features of rectal bleeding in rectal cancer?
Rectal bleeding in rectal cancer is bright red and mixed in volumes. There may be an alteration in bowel habit, and tenesmus may be present. Symptoms of metastatic disease may also be present.
What are the examination findings for rectal bleeding in rectal cancer?
Usually, an obvious mucosal abnormality is present. The lesion may be fixed or mobile, depending on the extent of the disease. The surrounding mucosa is often normal, although polyps may be present.
What are the minimal baseline investigations for patients presenting with rectal bleeding?
Digital rectal examination and procto-sigmoidoscopy.
Why is it unsatisfactory to attribute bleeding to haemorrhoids without accurate internal inspection?
Haemorrhoids are typically impalpable, so accurate internal inspection is necessary to confirm their presence as the cause of bleeding.
What is the recommended test for young patients with no other concerning features in the history and clear views cannot be obtained during sigmoidoscopy?
Bowel preparation with an enema followed by a flexible sigmoidoscopy.
What is the best test for patients presenting with features of altered bowel habit or suspicion of inflammatory bowel disease?
Colonoscopy
What is the recommended examination for patients suspected of having a fissure and experiencing excessive pain?
Examination under general or local anaesthesia.
In young patients with external stigmata of fissure and a compatible history, when is internal examination necessary?
If the fissure fails to heal after medical treatment.
What are the staging investigations for patients with rectal cancer?
MRI of the rectum to identify resection margin compromise and mesorectal nodal disease, and CT scanning of the chest, abdomen, and pelvis to stage for more distant disease.
What additional tests should be performed for female patients with a fissure in ano who are being considered for surgical sphincterotomy and have an obstetric history?
Ano rectal manometry testing and endo anal ultrasound.
What is the first-line treatment for fissure in ano?
GTN ointment 0.2% or diltiazem cream applied topically.
What treatment options are available for haemorrhoids?
For small internal haemorrhoids, injection sclerotherapy or rubber band ligation can be considered. For external haemorrhoids, haemorrhoidectomy is an option. Modern options include HALO procedure and stapled haemorrhoidectomy.
What is the recommended management for inflammatory bowel disease?
Medical management, although surgery may be needed for fistulating Crohn’s disease.
What surgical procedures are commonly performed for rectal cancer?
Anterior resection or abdomino-perineal excision of the colon and rectum. Total mesorectal excision is now the standard of care. Most resections below the peritoneal reflection will require defunctioning ileostomy. Preoperative radiotherapy is often necessary.
What is the typical presentation of colonic bleeding?
Bright red or dark red blood per rectum.
Why is melaena type stool rarely seen in colonic bleeding?
Blood in the colon has a powerful laxative effect and is rarely retained long enough for transformation to occur. Additionally, the digestive enzymes present in the small bowel are not present in the colon.
What percentage of patients presenting with haemochezia have an upper gastrointestinal source of bleeding?
Up to 15%
What is the general rule regarding the color of blood in right-sided bleeds versus left-sided bleeds?
Right-sided bleeds tend to present with darker colored blood than left-sided bleeds.
What are the presenting features of colitis?
Bleeding may be brisk in advanced cases, and diarrhea is commonly present. An abdominal x-ray may show a featureless colon.
What is the typical presentation of acute diverticulitis?
Acute diverticulitis is often not complicated by major bleeding, and diverticular bleeds often occur sporadically. 75% of these bleeds will cease spontaneously within 24-48 hours. The bleeding is often dark and of large volume.
How does haemorrhoidal bleeding typically present?
Bright red rectal bleeding that occurs post defecation, either onto toilet paper or into the toilet pan.
How do colonic cancers often present?
Colonic cancers often bleed, and for many patients, this may be the first sign of the disease. Major bleeding from early lesions is uncommon.
What is the common site of angiodysplasia in the colon?
The right side of the colon is more commonly affected by angiodysplasia.
What are the typical presenting features of haemorrhoidal bleeding?
Typically bright red bleeding occurring post defecation. Although patients may give graphic descriptions, bleeding of sufficient volume to cause hemodynamic compromise is rare.
What is the first-line management for lower gastrointestinal bleeding?
Supportive care, as endoscopy is rarely helpful in the acute setting.