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.
What is the recommended approach for suspected haemorrhoidal bleeding?
A proctosigmoidoscopy is reasonable, as attempts at full colonoscopy are usually time-consuming and often futile.
What is the standard procedure for stable patients with lower gastrointestinal bleeding?
A colonoscopy in the elective setting is the standard procedure for stable patients.
What is the standard procedure for unstable patients with lower gastrointestinal bleeding?
An angiogram (either CT or percutaneous) may be performed during a period of haemodynamic instability to identify a bleeding point or angiodysplasia.
What are the indications for surgery in cases of lower gastrointestinal bleeding?
Patients over 60 years old, continued bleeding despite endoscopic intervention, recurrent bleeding, and known cardiovascular disease with a poor response to hypotension.
What is the recommended approach for life-threatening bleeding in lower gastrointestinal bleeding?
Selective mesenteric embolization should be considered, especially during a period of relative haemodynamic instability.
What should be done if the source of colonic bleeding is unclear?
Perform a laparotomy, followed by on-table colonic lavage, and then attempt a resection. Blind subtotal colectomy is not advised.
What are the recommendations for the management of acute lower gastrointestinal bleeding?
Consider admission for patients over 60 years old, those who are haemodynamically unstable with profuse PR bleeding, those on aspirin or NSAIDs, and those with significant co-morbidity. All patients should undergo a history and examination, PR and proctoscopy, and colonoscopic haemostasis should be aimed for in post-polypectomy or diverticular bleeding.
What are the recommended management considerations for patients with ulcerative colitis and significant hemorrhage?
A subtotal colectomy is the standard approach, particularly if medical management has already been tried and proven ineffective.
What type of epithelium do anal cancers arise from?
Squamous epithelium of the anal canal
Where do anal cancers typically arise in relation to the dentate line?
Inferior to the dentate line
What is anal cancer strongly linked to?
HPV type 16 infection
What are some other risk factors for anal cancer?
Ano-receptive intercourse, smoking, and immunosuppression
Where does lymphatic spread typically occur in anal cancer?
To the inguinal nodes
What are the presenting symptoms of anal cancer?
Anal discomfort, discharge, or pruritus
How is the diagnosis of anal cancer made?
By endoscopic ultrasound examination (EUA) and biopsies
What is the staging method for anal cancer?
CT scanning of the chest, abdomen, and pelvis
What is the first-line treatment for anal cancer?
Typically chemoradiotherapy
What is the second-line treatment for non-metastatic anal cancer?
Salvage radical abdominoperineal excision of the anus and rectum
What are the most common causes of colonic obstruction?
Malignancy (60%) and diverticular disease (20%)
What percentage of colonic obstruction cases are due to volvulus affecting the colon?
5%
What is an important differential diagnosis to consider in cases of colonic obstruction?
Acute colonic pseudo-obstruction
What is a rare but recognized cause of intussusception affecting the colon?
Tumors, especially in the adult population
What are the typical symptoms of a patient with colonic obstruction?
Gradual onset of progressive abdominal distension, colicky abdominal pain, obstipation or absolute constipation
What sign on examination is useful to elicit in cases of colonic obstruction?
Caecal tenderness
What imaging modality is commonly used as the first-line investigation for colonic obstruction?
CT scan
What is the recommended surgical treatment for right-sided lesions causing colonic obstruction?
Right hemicolectomy or its extended variant
What are the surgical options for left-sided lesions causing colonic obstruction?
Subtotal colectomy and anastomosis, left hemicolectomy with on-table lavage and primary anastomosis, left hemicolectomy and end colostomy formation, or colonic stent insertion
What is the recommended treatment for rectosigmoid lesions causing colonic obstruction?
Loop colostomy or high anterior resection, depending on the location of the lesion
What is considered a sign of impending perforation in large bowel obstruction?
A caecal diameter of 12cm or more in the presence of complete obstruction, with a competent ileocaecal valve and caecal tenderness.
What should be assessed on a plain abdominal x-ray in cases of suspected large bowel obstruction?
Caecal diameter and ileocaecal valve competency
What is the debated choice of imaging modality for large bowel obstruction?
CT scan versus gastrograffin enemas
Where are ileostomies typically fashioned?
In the right iliac fossa, forming a triangle between the anterior superior iliac spine, symphysis pubis, and umbilicus.
What is the recommended position for an ileostomy in relation to the umbilicus and anterior superior iliac spine?
It should lie one-third of the distance between the umbilicus and anterior superior iliac spine.
What size skin incision is typically made for an ileostomy?
A 2cm incision is made, followed by dissection through the rectus muscle.
How should the incision be made on the bowel during ileostomy creation?
A cruciate incision is made, generally dilated to admit two fingers.
What is the optimal length for the protrusion of the ileum through the incisions during ileostomy creation?
The ileum should be spouted to a final length of 2.5cm.
What problems can occur if an ileostomy is too short or too long?
Ileostomies that are too short may cause issues with appliance fixation, while those that are too long may lead to tension, ulceration, or prolapse.
What are some complications that can arise following ileostomy construction?
Common complications include dermatitis, bowel obstruction (usually adhesional), and prolapse.
What is the typical range of ileostomy output in a 24-hour period?
The output is usually in the range of 5-10ml per kilogram of body weight.
When does ileostomy output exceeding 20ml per kilogram of body weight in a 24-hour period require supplementary intravenous fluids?
When excessive fluid losses occur, supplementary intravenous fluids are administered.
How can excessive ileostomy output be managed?
Oral loperamide (up to 4mg four times a day) can be administered to slow down the output. Foods containing gelatine may also help thicken the output.
What causes pilonidal sinus?
It occurs as a result of hair debris creating sinuses in the skin (Bascom theory).
In which area of the body is pilonidal sinus commonly found in male patients after puberty?
It is usually found in the natal cleft (the area between the buttocks) of male patients after puberty.
What is the composition of the sinus wall?
The opening of the sinus is lined by squamous epithelium, while the majority of the wall consists of granulation tissue.
Which population is more commonly affected by pilonidal sinus?
It is more common in Caucasians due to their hair type and growth patterns.
What is a potential complication associated with chronic pilonidal sinus disease?
There have been reports of up to 50 cases of squamous cell carcinoma in patients with chronic pilonidal sinus disease.
How does pilonidal sinus typically present clinically?
The sinus presents when acute inflammation occurs, resulting in an abscess. Patients may experience cycles of being asymptomatic and periods of pain and discharge from the sinus.
Why should definitive treatment be avoided during acute infection or abscess?
Undertaking definitive treatment during acute infection or abscess can lead to treatment failure.
What are two definitive treatment options for pilonidal sinus?
The Bascom procedure involves excision of the pits and obliteration of the underlying cavity, while the Karydakis procedure involves wide excision of the natal cleft and recontouring of the surface once the wound is closed.
What is the benefit of the Karydakis procedure?
The Karydakis procedure helps avoid shearing forces that can break off hairs and has shown reasonable results.
What are the common positions of haemorrhoids?
They are commonly located at the 3, 7, and 11 o’clock positions.
Are haemorrhoids classified as internal or external?
They can be either internal or external.
What are the treatment options for haemorrhoids?
Treatment options include conservative management, rubber band ligation, and haemorrhoidectomy.
Where is a fissure in ano typically located?
A fissure in ano is usually located in the midline at the 6 o’clock position (posterior midline), with the possibility of being at the 12 o’clock position as well.
Where is a chronic fissure commonly found?
A chronic fissure is commonly found distal to the dentate line.
What are the components of the triad associated with a chronic fissure lasting longer than 6 weeks?
The triad includes an ulcer, sentinel pile, and enlarged anal papillae.
What are some causes of proctitis?
Proctitis can be caused by Crohn’s disease, ulcerative colitis, and Clostridium difficile infection.
What are the common positions for an ano rectal abscess?
Ano rectal abscesses can occur in perianal, ischiorectal, pelvirectal, and intersphincteric positions.
What is the usual cause of an anal fistula?
Anal fistulas are usually a result of a previous ano-rectal abscess.
What are the different types of anal fistulas based on their location?
The types include intersphincteric, transsphincteric, suprasphincteric, and extrasphincteric, which can be determined using Goodsall’s rule.
What are some common causes of rectal prolapse?
Rectal prolapse is commonly associated with childbirth and rectal intussusception. It can be internal or external.
What are some causes of pruritus ani?
Pruritus ani can have systemic and local causes.
Which type of anal neoplasm is the most common?
Squamous cell carcinoma is the most common type of anal neoplasm, unlike adenocarcinoma which is more common in the rectum.
What is associated with solitary rectal ulcer?
Solitary rectal ulcer is associated with chronic straining and constipation. Histology shows mucosal thickening and fibromuscular obliteration.
Who is most commonly affected by rectal prolapse?
Rectal prolapse is more common, especially in multiparous women.
What are the two types of rectal prolapse?
Rectal prolapse can be internal or external.
How does internal rectal prolapse typically present?
Internal rectal prolapse may have an insidious presentation.
What are the potential long-term effects of external rectal prolapse?
External rectal prolapse can ulcerate and impair continence over time.
What diagnostic tests are used to evaluate rectal prolapse?
Diagnostic workup may include colonoscopy, defecating proctogram, ano rectal manometry studies, and examination under anesthesia if there is doubt.
What is the initial treatment for rectal prolapse in the acute setting?
In the acute setting, the prolapse can be reduced (covering it with sugar may help reduce swelling).
What is the Delormes procedure used for?
The Delormes procedure, which excises mucosa and plicates the rectum, may be used for external prolapse (with high recurrence rates).
What is the Altmeirs procedure used for?
The Altmeirs procedure, which resects the colon via the perineal route, has lower recurrence rates but carries the risk of anastomotic leak.
What is rectopexy?
Rectopexy is an abdominal procedure that elevates and supports the rectum, usually at the level of the sacral promontory.
How can postoperative constipation be reduced after rectopexy?
Limiting the dissection to the anterior plane (laparoscopic ventral mesh rectopexy) may help reduce postoperative constipation.
What is diverticular disease?
Diverticular disease is the herniation of colonic mucosa through the muscular wall of the colon.
Where is the usual site of diverticula formation?
Diverticula typically form between the taenia coli, where vessels pierce the muscle to supply the mucosa. The rectum, which lacks taenia, is often spared.
What are the common symptoms of diverticular disease?
Symptoms may include altered bowel habit, bleeding, and abdominal pain.
What are the potential complications of diverticular disease?
Complications can include diverticulitis, hemorrhage, fistula development, perforation with fecal peritonitis, abscess formation, and diverticular phlegmon.
What diagnostic tests are used for diverticular disease?
Diagnostic workup may include colonoscopy, CT cologram, or barium enema. These tests can identify diverticular disease, but excluding cancer (particularly in diverticular strictures) can be more challenging.
How should acutely unwell surgical patients with diverticular disease be investigated?
Plain abdominal films and an erect chest x-ray can identify perforation. An abdominal CT scan (not a CT cologram) with oral and intravenous contrast can help identify acute inflammation and local complications such as abscess formation.
What are the treatment options for diverticular disease?
Treatment may involve increasing dietary fiber intake. Mild attacks of diverticulitis can be managed conservatively with antibiotics. Peri colonic abscesses may require surgical or radiological drainage. Recurrent episodes of acute diverticulitis may indicate the need for a segmental resection. Hinchey IV perforations (generalized fecal peritonitis) typically require resection and may involve creating a stoma.
What is the severity classification system for diverticular disease called?
The severity classification system for diverticular disease is known as the Hinchey classification. It includes four stages: I) para-colonic abscess, II) pelvic abscess, III) purulent peritonitis, and IV) fecal peritonitis.
Can surgical resection cure ulcerative colitis?
Yes, surgical resection (Proctocolectomy) can cure ulcerative colitis.
Why is dysplastic transformation of the colonic epithelium an absolute indication for proctocolectomy?
Dysplastic transformation of the colonic epithelium with associated mass lesions is an absolute indication for proctocolectomy due to the risk of malignant transformation.
What is the recommended thromboprophylaxis for patients with inflammatory bowel disease (IBD)?
Patients with IBD have a high incidence of deep vein thrombosis (DVT), and appropriate thromboprophylaxis is mandatory.
How should emergency presentations of poorly controlled colitis that fail to respond to medical therapy be managed?
Emergency presentations of poorly controlled colitis that fail to respond to medical therapy should usually be managed with a subtotal colectomy. Excision of the rectum is not generally performed in the emergency setting.
What are the restorative options for ulcerative colitis (UC)?
Restorative options for UC include an ileoanal pouch, which can only be performed while the rectum is in situ and cannot usually be performed as a delayed procedure following proctectomy.
Is surgical resection a cure for Crohn’s disease?
No, surgical resection of Crohn’s disease does not equate to a cure but may provide substantial symptomatic improvement.
What are the indications for surgery in Crohn’s disease?
Indications for surgery in Crohn’s disease include complications such as fistulae, abscess formation, and strictures.
How can short bowel syndrome be avoided during small bowel resections for Crohn’s disease?
Localised stricturoplasty may allow preservation of intestinal length and help avoid short bowel syndrome during extensive small bowel resections for Crohn’s disease.
What diagnostic tests are usually involved in staging Crohn’s disease?
Staging of Crohn’s disease usually involves colonoscopy and a small bowel study, such as MRI enteroclysis.
What are the diagnostic criteria for irritable bowel syndrome (IBS) according to ROME III?
Recurrent abdominal pain or discomfort at 3 days per month for the past 3 months, associated with at least two of the following: improvement with defecation, onset associated with a change in the frequency of stool, onset associated with a change in the form of the stool. Additional features such as lethargy, nausea, backache, and bladder symptoms may also support the diagnosis.
What are the red flag features that should be inquired about in patients with suspected IBS?
Rectal bleeding, unexplained/unintentional weight loss, family history of bowel or ovarian cancer, and onset of symptoms after 60 years of age.
What investigations are suggested for patients with suspected IBS?
Full blood count, ESR/CRP, coeliac disease screen (tissue transglutaminase antibodies), colonoscopy (if worrying symptoms or positive family history), thyroid function tests, and glucose (to ensure not diabetic).
What criteria does NICE (National Institute for Health and Care Excellence) suggest for diagnosing IBS?
NICE criteria state that blood tests alone will suffice in people fulfilling the diagnostic criteria for IBS. However, luminal colonic studies should be considered early in patients with altered bowel habit referred to the hospital, and a diagnosis of IBS should still be largely one of exclusion.
What are the recommended treatment options for IBS?
Treatment for IBS usually involves reducing fiber intake, tailored prescriptions of laxatives or loperamide based on the clinical picture, dietary modifications such as caffeine avoidance and consuming fewer carbonated drinks. Low-dose tricyclic antidepressants may be considered if pain is a dominant symptom, and biofeedback may also help.
What is a common cause of colonic obstruction?
Cancer is a common cause of colonic obstruction.
What are the features of colonic obstruction caused by cancer?
Colonic obstruction caused by cancer typically has an insidious onset, a history of progressive constipation, systemic features (e.g., anemia), abdominal distension, and absence of bowel gas distal to the site of obstruction.
What are the treatment options for colonic obstruction caused by cancer?
Treatment options include laparotomy and resection, stenting, defunctioning colostomy, or bypass.
How is the diagnosis of colonic obstruction caused by cancer established?
The diagnosis is usually established through methods such as contrast enema or endoscopy.
What can cause colonic obstruction due to diverticular stricture?
Colonic obstruction can be caused by diverticular stricture, which is usually associated with a history of previous acute diverticulitis and a long history of altered bowel habit. Imaging or endoscopy may show evidence of diverticulosis.
What is volvulus, and which part of the colon is commonly affected?
Volvulus is the twisting of the bowel around its mesentery. In 76% of cases, the sigmoid colon is affected.
What is the recommended treatment for colonic obstruction caused by diverticular stricture?
Once the diagnosis is established, surgical resection is usually the recommended treatment. Colonic stenting should not be performed for benign disease.
What is the initial treatment for volvulus-induced colonic obstruction?
The initial treatment is to untwist the loop, and a flexible sigmoidoscopy may be needed. Patients with clinical evidence of ischemia should undergo surgery, and those with recurrent volvulus should undergo resection.
What is acute colonic pseudo-obstruction?
Acute colonic pseudo-obstruction is a condition that mimics large bowel obstruction but has no lesion. It is usually associated with metabolic disorders and often has a cutoff in the left colon.
What are the treatment options for acute colonic pseudo-obstruction?
Treatment options include colonoscopic decompression, correcting metabolic disorders, intravenous neostigmine, or surgery if necessary.
What are the symptoms and signs of volvulus-induced colonic obstruction?
Patients with volvulus-induced colonic obstruction typically present with abdominal pain, bloating, and constipation. Examination usually shows asymmetrical distension. Plain X-rays may show a massively dilated sigmoid colon with loss of haustra, and a U shape is typical.
What is the target of Adalimumab, Infliximab, and Etanercept?
These agents target TNF alpha.
What are the uses of Adalimumab, Infliximab, and Etanercept?
They are used as TNF alpha inhibitors in Crohn’s disease and rheumatoid disease.
How is acute colonic pseudo-obstruction diagnosed?
All patients with suspected acute colonic pseudo-obstruction should undergo a contrast enema, which may also be therapeutic.
What is the target of Bevacizumab?
Bevacizumab targets VEGF (vascular endothelial growth factor) as an anti-angiogenic agent.
What is the target of Bevacizumab?
Bevacizumab targets VEGF (vascular endothelial growth factor) as an anti-angiogenic agent.
What are the uses of Bevacizumab?
Bevacizumab is used in colorectal cancer, renal cancer, and glioblastoma.
What is the target of Trastuzumab?
Trastuzumab targets the HER receptor.
What is the use of Trastuzumab?
Trastuzumab is used in breast cancer.
What is the target of Imatinib?
Imatinib is a tyrosine kinase inhibitor.
What are the uses of Imatinib?
Imatinib is used in gastrointestinal stromal tumors and chronic myeloid leukemia.
What is the target of Basiliximab?
Basiliximab targets the IL2 binding site.
What is the use of Basiliximab?
Basiliximab is used in renal transplants.
What is the target of Cetuximab?
Cetuximab is an epidermal growth factor inhibitor.
What is the use of Cetuximab?
Cetuximab is used in EGF-positive colorectal cancers.
What is the main goal of screening for colorectal cancer?
Screening for colorectal cancer aims to reduce mortality by 16%.
Who is eligible for the national screening programme offered by the NHS?
All men and women aged 60 to 69 years are eligible for screening every 2 years. Patients aged over 70 years may request screening.
What tests are used for screening eligible patients?
Eligible patients are sent faecal occult blood (FOB) tests through the post, which are being replaced by FIT testing.
What happens if a patient has abnormal screening results?
Patients with abnormal results are offered a colonoscopy.
What does the NHS BOSS flexible sigmoidoscopy screening involve?
The NHS BOSS flexible sigmoidoscopy screening comprises a single flexible sigmoidoscopy for patients aged 55 years.
What are the approximate findings during colonoscopy?
During colonoscopy, approximately 5 out of 10 patients will have a normal exam, 4 out of 10 patients will have polyps that may be removed, and 1 out of 10 patients will be found to have cancer.
What is the gold standard for diagnosis of colorectal cancer?
Colonoscopy is the gold standard for diagnosis, provided it is complete and good mucosal visualization is achieved.
Which symptoms indicate the need for referral regarding colorectal cancer?
Patients with altered bowel habit for more than six weeks, new onset rectal bleeding, or symptoms of tenesmus should be referred for further evaluation.
What are the staging procedures for colonic and rectal cancer?
Patients with colonic cancer will undergo chest/abdomen and pelvic CT staging, while patients with rectal cancer will also have pelvic MRI scanning to evaluate the mesorectum.
What are the preferred systems for staging colorectal cancer?
For examination purposes, the Dukes and TNM systems are preferred for staging colorectal cancer.
What is the main tumor marker in colorectal cancer?
Carcinoembryonic antigen (CEA) is the main tumor marker in colorectal cancer.
What should be considered when interpreting CEA levels?
Not all tumors secrete CEA, and it may be raised in conditions such as IBD. However, absolute levels roughly correlate with disease burden, and it is once again being used routinely in follow-up.
What is colonic pseudo-obstruction characterized by?
Colonic pseudo-obstruction is characterized by progressive and painless dilation of the colon.
What are the symptoms of colonic pseudo-obstruction?
The abdomen may become grossly distended and tympanic, but there is usually little pain unless complications like bowel necrosis or perforation occur.
How is colonic pseudo-obstruction diagnosed?
Diagnosis involves excluding a mechanical bowel obstruction using a plain film and contrast enema.
When is surgery required for colonic pseudo-obstruction?
Surgery may be required in rare cases when other treatments are ineffective.
What is the next step if supportive measures do not work?
Patients who do not respond to supportive measures may be treated with attempted colonoscopic decompression and/or the drug neostigmine.
What is the underlying cause of colonic pseudo-obstruction?
The underlying cause is usually an electrolyte imbalance, and the condition will resolve with correction of the imbalance and supportive care.
What symptoms are associated with internal rectal prolapse?
Patients with internal rectal prolapse may experience constipation, obstructed defecation, and occasionally fecal incontinence due to internal intussusception of the rectum.
What are the two types of rectal prolapse?
Rectal prolapse can be divided into internal and external prolapse.
What is the characteristic feature of external rectal prolapse?
External rectal prolapse is characterized by a full-thickness external protrusion of the rectum.
What are the risk factors for rectal prolapse?
Risk factors for rectal prolapse include multiparity (having multiple pregnancies), pelvic floor trauma, and connective tissue disorders.
How is internal prolapse diagnosed?
Internal prolapse can be identified through defecating proctography (a test that evaluates the rectum during defecation) and examination under anesthesia.
What diagnostic procedure should be done to exclude sinister pathology?
Endoscopy should be performed to exclude any underlying sinister pathology.
What are the treatment options for rectal prolapse?
Treatment options include perineal approaches (such as the Delorme’s operation and Altmeirs operation) and abdominal procedures like rectopexy.
What is rectopexy?
Rectopexy is an abdominal procedure where the rectum is mobilized and fixed onto the sacral promontory. It may involve the insertion of a prosthetic mesh.
What is the Thirsch tape procedure?
The Thirsch tape procedure, which is mostly historical, involves encircling the rectum with tape or wire. It may be used in a palliative setting.
What is the genetic defect associated with familial adenomatous polyposis (FAP)?
FAP is caused by a mutation in the APC gene (in 80% of cases) and follows a dominant inheritance pattern.
What are the typical features of FAP?
FAP is characterized by the presence of over 100 colonic adenomas, with a 100% risk of developing cancer. About 20% of cases are new mutations.
How is FAP screened and managed?
If known to be at risk, predictive genetic testing is recommended during teenage years. Annual flexible sigmoidoscopy is recommended from age 15, and if polyps are found, resectional surgery is performed.
How is MYH-associated polyposis managed?
Once identified, resection and ileoanal pouch reconstruction are recommended. Regular colonoscopy is suggested for the attenuated phenotype.
What are the associated disorders with FAP?
FAP is associated with gastric fundal polyps (50%), duodenal polyps (90%), and abdominal desmoid tumors. Severe duodenal polyposis carries a 30% risk of cancer at 10 years.
What is MYH-associated polyposis and its genetic defect?
MYH-associated polyposis is caused by a biallelic mutation of the mut Y human homologue (MYH) on chromosome 1p, following a recessive inheritance pattern.
What are the features of MYH-associated polyposis?
MYH-associated polyposis presents with multiple colonic polyps, and right-sided cancers have a later onset compared to FAP. The lifetime cancer risk is 100% by age 60.
What are the associated features and risks of Peutz-Jeghers syndrome?
Peutz-Jeghers syndrome is characterized by multiple benign intestinal hamartomas, episodic obstruction, and intussusception. There is an increased risk of various GI cancers, as well as breast, ovarian, cervical, pancreatic, and testicular cancers.
How is Peutz-Jeghers syndrome screened and managed?
Annual examination and pan-intestinal endoscopy every 2-3 years are recommended for surveillance.
How is Cowden disease managed?
Individualized screening based on targeted approaches is recommended. Surveillance for breast cancer, thyroid cancer and non-toxic goiter, and uterine cancer is important.
What are the features and risks associated with Cowden disease?
Cowden disease is characterized by macrocephaly, multiple intestinal hamartomas, multiple trichilemmomas, and an 89% risk of cancer at any site. The risk of colorectal cancer is 16%.
What is the genetic defect associated with HNPCC (Lynch syndrome)?
HNPCC is caused by germline mutations in DNA mismatch repair genes.
What are the common cancers associated with HNPCC?
HNPCC is associated with colorectal cancer (30-70% risk), endometrial cancer (30-70% risk), and gastric cancer (5-10% risk). Colonic tumors in HNPCC are likely to be right-sided and mucinous.
How is HNPCC screened and managed?
Colonoscopy every 1-2 years from age 25 is recommended, with consideration of prophylactic surgery. Extra-colonic surveillance is also recommended.
Where are most fissures located?
Most fissures are idiopathic and present as a painful mucocutaneous defect in the posterior midline (90% of cases).
What are anal fissures?
Anal fissures are a common cause of painful, bright red, rectal bleeding.
Are fissures more likely to be located anteriorly in females?
Yes, fissures are more likely to be anteriorly located in females, especially if they have had multiple pregnancies.
What can multiple fissures or fissures located at other sites indicate?
Multiple fissures or fissures located at other sites are more likely to be due to an underlying cause.
What diseases are associated with fissure in ano?
Fissure in ano can be associated with Crohn’s disease, tuberculosis, and internal rectal prolapse.
How is anal fissure diagnosed?
In most cases, the defect can be visualized as a posterior midline epithelial defect. If examination findings are unclear, an examination under anesthesia may be helpful. Atypical presentations should be investigated with colonoscopy and biopsies.
What are the options for resistant cases of anal fissure?
Resistant cases may benefit from injection of botulinum toxin or lateral internal sphincterotomy (be cautious in females). Advancement flaps can also be used for treatment.
What is the recommended treatment for anal fissure?
Stool softeners are important to prevent recurrent symptoms. The most effective first-line treatments are topically applied GTN (0.2%) or Diltiazem (2%) paste. Diltiazem is better tolerated in terms of side effects.
What is the best treatment option for anal fissure in terms of healing rates?
Sphincterotomy has the best healing rates, but it is associated with potential incontinence to flatus in up to 10% of patients in the long term.
What is the characteristic abdominal pain in appendicitis?
Peri-umbilical abdominal pain that radiates to the right iliac fossa due to localized inflammation of the peritoneum surrounding the appendix.
Is diarrhea a common symptom of appendicitis?
No, diarrhea is rare in appendicitis. However, pelvic appendicitis may cause local rectal irritation and loose stools.
Is persistent vomiting common in appendicitis?
No, marked and persistent vomiting is unusual in appendicitis.
What is the typical temperature range in appendicitis?
Mild pyrexia is common, with temperatures usually ranging from 37.5 to 38°C. Higher temperatures are more typical of conditions like mesenteric adenitis.
Is loss of appetite common in appendicitis?
Yes, anorexia is very common in appendicitis. It is unusual for patients with appendicitis to feel hungry.
What signs may be present during examination for appendicitis?
Perforation may lead to generalized peritonitis, while retrocecal appendicitis may have relatively few signs. Digital rectal examination may reveal a boggy sensation if a pelvic abscess is present or tenderness with a pelvic appendix.
When is ultrasound useful in the diagnosis of appendicitis?
Ultrasound is useful, especially in females when pelvic organ pathology is suspected. Although the appendix may not always be visualized, the presence of free fluid should raise suspicion.
What findings support the diagnosis of appendicitis?
Typically, raised inflammatory markers along with a compatible history and examination findings should be enough to justify an appendectomy.
What is the treatment for appendicitis?
Appendectomy, which can be performed via an open or laparoscopic approach. Administration of metronidazole helps reduce wound infection rates. In cases of perforated appendicitis, copious abdominal lavage is required. Patients without peritonitis but with an appendix mass should receive broad-spectrum antibiotics, and an interval appendectomy should be considered.
What should be considered in older patients with appendicitis?
In older patients, underlying caecal malignancy or perforated sigmoid diverticular disease should be considered.
What are the recommended blood tests for elective surgery?
Full blood count (FBC), Urea and electrolytes (U+E), Liver function tests (LFTs), clotting profile, blood group and save. Urine analysis, pregnancy test, and sickle cell test may also be necessary.
What additional tests may be required depending on the procedure and patient fitness?
Additional tests such as ECG and chest x-ray may be needed depending on the proposed procedure and patient fitness.
What are the considerations for diabetic patients undergoing surgery?
Diabetic patients have a higher risk of complications. Poorly controlled diabetes increases the risk of wound infections. Patients with diet or tablet-controlled diabetes may omit medication and monitor blood glucose levels regularly. Poorly controlled or insulin-dependent diabetics may require an intravenous sliding scale and potassium supplementation. Diabetic cases should be operated on first.
What should be assessed and planned for in terms of thromboprophylaxis?
Assess and plan for risk factors for deep vein thrombosis (DVT) development and formulate a plan for thromboprophylaxis.
What are the key steps for preparation in emergency surgery?
Stabilize and resuscitate as necessary. Assess the need for antibiotics and determine the timing and administration method. Inform the blood bank if major procedures are planned, especially if coagulopathies are present or anticipated. Obtain consent and inform relatives.
What special preparations may be necessary for specific procedures?
Thyroid surgery may require a vocal cord check. Methylene blue may be considered for identifying parathyroid glands during parathyroid surgery. Sentinel node biopsy may involve a radioactive marker or patent blue dye. Surgery involving the thoracic duct may require the administration of cream. Pheochromocytoma surgery may need alpha and beta blockade. Surgery for carcinoid tumors may require covering with octreotide. Bowel preparation is especially important for colorectal cases, especially left-sided surgery. Thyrotoxicosis may require Lugol’s iodine or medical therapy.
How many new cases of colorectal cancer are diagnosed annually?
Approximately 150,000 new cases are diagnosed each year.
What is the proportion of sporadic and familial cases of colorectal cancer?
About 75% of cases are sporadic, while 25% have a family history of the disease.
What is the spectrum of colorectal tumors?
Colorectal tumors range from adenomas to polyp cancers and frank malignancy.
What are the different types of polyps?
Polyps can be categorized as neoplastic polyps (including adenomatous polyps) and non-neoplastic polyps.
Why should most polyps identified during colonoscopy be removed?
Most polyps identified during colonoscopy should be removed because they have the potential to progress to cancer.
What are the characteristics of adenomas that correlate with malignant potential?
Three characteristics of adenomas that correlate with malignant potential are increased size, villous architecture, and dysplasia.
What is the adenoma-carcinoma sequence?
The adenoma-carcinoma sequence describes the transformation from polyp to cancer. Genetic changes, such as APC, c-myc, K RAS mutations, and p53 deletions, accompany this transition.
