Colon 1e43

Colon

All are true statements regarding appendices

epiploicae EXCEPT a) Extends the whole length of colon except rectum b) More prominent in sigmoid colon c) Flat in right sided colon d) Absent in appendix

Ans - a

Length of colon – longer in females (155 vs 145 cm)

difference mainly due to length of transverse colon Jackson’s membrane – flimsy adhesions between abdominal wall and anterior taenia of ascending colon Narrowest portion of colon – rectosigmoid – no sphincter Cecum breadth more than length (7.5cm vs 6 cm) Ileocecal valve   

Bauhn Both circular and longitudinal muscle Misnomer – sphincter function in terminal ileum

Cecocolonic junction – true sphincter

All are true statements regarding Vermiform appendix

EXCEPT a) Appendicular artery is a branch of posterior cecal artery b) Bloodless fold of treves represent superior ileocecal fold c) Most common location is retrocolic d) Gerlachs valve at appendicular orifice is not a true valve Ans - b

Vascular supply of colon   

SMA branches – ileocolic most constant Right colic most variable & Absent in 2-18% Most common variation of right colic – from middle colic

Middle colic absent in 4-20% SMA – L1 IMA – L3 Arch of riolan (MMA)   

Between left colic and middle colic present in 2/3 of patients Synonyms - Arch of treves, Artery of drummond

Lymph nodes along middle colic artery are a) Epicolic nodes b) Paracolic nodes c) Intermediate nodes d) Principal nodes

Ans - c

Risk of volvulus is low in which type of rotation

anomaly a) Non rotation b) Reverse rotation c) Nonrotation of duodenal jejunal limb with normal rotation and fixation of cecocolic limb d) Normal rotation of duodenal jejunal limb with non rotation of cecocolic limb Ans - c

Difference in presentation of malrotation in adults

and neonates – volvulus uncommon in adults Barium meal follow through investigation of choice – birds beak Management of old asymptomatic patients with malrotation diagnosed preop Incidental malrotation detected intra-op – always corrected Malrotation associated with life threatening disorders (CDH) – not corrected

All are true statements regarding right mesocolic hernia

EXCEPT a) Caused by failure of the small bowel to rotate to the left with the right coloncontinuing to rotate anterior to it b) Should be treated even detected incidentally c) Opening of the herniasac lies above the ascending branch of the left colic artery andthe inferior mesenteric vein. d) Superior mesenteric artery forms the anterior edge of the herniasac Key – c

Mesocolic hernias

Left mesocolic hernia occurs through vascular arch of treitz

– formed by IMA and left colic artery Left mesocolic hernia more common than left IMA and IMV lies on the right margin of sac Right mesocolic hernia – SMA lies on medial border of sac Should be treated even detected incidentally as the lifetime

riskfor bowel incarceration is approximately50%.

All are true statements regarding CT colonography

Except a) Requires bowel preparation b) Done in prone position c) Requires bowel inflation with air d) Accepted as the leading imaging technique for colorectal cancer screening Key - b

MR colonography Specific contraindications - claustrophobia, metallic implants, or cardiac

pacemakers Preparation and position – similar to CT colonography Antispasmodic – glucagon (IC valve reflux  poor distension) or buscopan MR colonography types Bright-lumen MR colonography   



istration of a gadolinium chelate–spiked enema Less popular Filling defects, including air bubbles and residual stool, that fail to displace despite dual positioning can be mistaken for true polyps Precludes the intravenous istration of gadopentetate dimeglumine as a troubleshooting approach to helping differentiate stool from polyps and cancer

Dark-lumen approach - istration of water, carbon dioxide, room air,

or fat.

The principal short chain fatty acid in large intestine

a) Acetate b) Propionate c) Butyrate d)Succinate Key – a

• The three primary fatty acids produced are acetate,

propionate, and butyrate in a ratio of 3 : 1: 1. • If the question is SCFA which is the primary energy source for colonic epithelial cells then Butyrate is the answer. Myenteric plexus and interstitial cells regulate motility Submucous plexus (Henle’s) regulate mucosal absorption Na – only absorbed K & Cl – absorbed and secreted Hco3 – only secreted

All are true statements regarding scintigraphic

assessment of colonic transit study EXCEPT a) Faster than radiopaque marker study b) Radiation exposure less compared to radiopaque marker study c) High geometric center is suggestive of pelvic outlet obstruction d) Radiolabelled delayed release activated charcoal or polystrene pellets used Key - b

Geometric center = proportion of counts x

weighing factor

Colonic transit study - methods Radioopaque marker     

capsule containing 24 radiopaque markers on days 1, 2, and 3 count remaining markers on a plain abdominal radiograph on days 4 and 7. 68 or fewer markers remaining in the colon - normal More than 68 markers indicates - slow transit constipation Retention of more than 20% of the markers at 120 hours is indicative of prolonged colonic transit.

Wireless Motility Capsule  

pH rises abruptly (by >2 units) when the capsule exits the stomach drops rapidly (by >1 unit) when it crosses the ileocecal valve.

Barostat better than manometry for measuring colonic motility

All are risk factors for colonic ischemia EXCEPT a) Cocaine abuse b) Long distance running c)Epstein Barr virus infection d) E. coli O157:H7 infection Key – c

Colonic ischemia – predisposing factors aortic surgery, arteriosclerotic disease, and

conditions causing transient hypotension oral contraceptives, cocaine abuse, hereditary coagulopathies, long distance running, and certain bacterial pathogens, including cytomegalovirus (CMV) and E. coli O157:H7.

True statement regarding Colonic ischemia A) Angiography is a valuable investigation to plan

management B) Revascularisation should be attempted if the patient is hemodynamically stable at the time of surgery C) Symptomatic colonic stricture secondary to colonic ischemia usually affects splenic flexure colon D) Resection of the strictured segment secondary to colonic ischemia with primary anastomosis is safe. Key – d

Colonic ischemia Arteriography is not indicated unless it is believed that acute mesenteric

ischemia involves the small intestine. Arteriography does not change the management or outcome of clinically apparent Colonic ischemia. Unlike mesenteric ischemia involving the small bowel, revascularization procedures to establish blood flow to the colon are not indicated. Chronic sequelae of CI include stricture formation and chronic segmental colitis. Strictures can be symptomatic, depending on their location and diameter. Strictures usually affect the sigmoid colon. Resection of the strictured segment with primary anastomosis is generally advocated for relatively healthy patients.

Colonic ischemia Special features of colonic circulation  

Increased motor activity is associated with decreased flow Most affected by autonomic circulation

Segment of colon more prone for ischemia – sigmoid

followed by splenic flexure Colonoscopy with minimal air insufflation – inv. Of choice Thumb printing sign  



Ba enema /x-ray Corresponds to hemorrhagic bullae (due to bleeding into submucosa) seen in colonoscopy Usually disappears in 1-2 weeks. If it persists s/o – lymphoma or amyloidosis

Treatment of choice for colonic inertia/slow transit

constipation a) Total colectomy with IPAA b) Subtotal colectomy with Ileorectal anastomosis c) Subtotal colectomy with Ileosigmoid anastomosis d) Subtotal colectomy with cecorectal anastomosis Key - b

constipation Etiology for STC – decrease in interstitial cells of cajal Algorithm for constipation evaluation 

Rule out organic cause  colonic transit study  do pelvic floor assessment with EMG or defecography

Segmental colonic transit study  no adv  segmental

resection  dilatation of remaining segments Small bowel transit study should be done before surgical treatment of STC   

Breath hydrogen Plasma sulfapyridine Scintigraphic study

 50 year old male with abdominal distension and constipation.

On examination there is tenderness in the left lower quadrant. Abdominal x-rays reveal a markedly dilated sigmoid colon that resembles a bent inner tube. Next line of management is A) CT abdomen B) Contrast enema C) Tube decompression D) Exploratory laparotomy Key – d

Colonic volvulus Pregnancy – risk factor for sigmoid volvulus Sigmoid volvulus  

Most common cause of large bowel obstruction in pregnant females Second most common cause of bowel obstruction after bowel adhesions

Cecal and sigmoid volvulus – clockwise rotation Cecal bascule  cecopexy, cecal volvulus – right

hemicolectomy Colonic volvulus with vomiting as earliest feature  transverse colon volvulus  compression of DJ junction Transverse colon volvulus treatment 

Extended right hemicolectomy or subtotal colectomy with IRA

Colonic intussusception Most common type of intussusception in adults with

increased incidence of subacute or recurrent attacks Attempt to reduce only in long segment intussusception without gangrene Predisposing factors   

Previous abdominal surgery Pregnancy constipation

Recurrent volvulus – rule out STC

All the following signs are seen in sigmoid volvulus

EXCEPT A) “coffee bean” sign B) “bird’sbeak” sign C) “whorl sign” D) “coiled spring” sign Key – d

All are true statements regarding ileosigmoid

knotting EXCEPT Common in India High fiber diet is a predisposing factor Long small bowel mesentry is a risk factor Long redundant sigmoid is a risk factor Key – d

All are true statements regarding colonic pseudo

obstruction EXCEPT A) Secondary more common than primary pseudoobstruction B) In Acute pseudoobstruction sigmoid colon is most commonly affected C) Chronic colonic pseudoobstruction also affects small bowel D) Neostigmine is useful for treatment Key –b

Reason for decrease in colonic transit after left colectomy Colonoscopic decompression vs neostigmine

Earliest sign of colonic vascular ectasia in

angiography A) Dilated tortuous submucosal vein B) Vascular tufts C) Early filling submucosal vein D) contrast extravasation from dilated submucosal vein Ans - A

Vascular ectasia - pathogenesis

Coagulation with heater probe/NdYAG laser –

treatment of choice Angiographic treatment 



Vasopressin iv and intra-arterial equal results – left colon bleeding Intra-arterial vasopressin – right colon bleeding

Surgery – right hemicolectomy Type of surgery not changed by presence of

diverticula in left colon

Etiology of lower GI bleed West

India

Rule out upper GI source

Colonoscopy – issues?

Early colonoscopy should be done? 

Major bleeding that has caesed and non major bleeding

Should colonoscopy be done after bowel

preparation? 

preferable

Radionuclide scanning Technetium labelled RBC (preferred because of long

t1/2) or sulphur colloid scan (uptake by liver /spleen obscures bleeding from flexures) Sensitive (0.1ml/min) less specific Role in acute lower GI bleed 

Guide in hemodynamically stable major lower GI bleed who is a candidate for angiography

Selective mesenteric angiography Order  SMA  IMA  CA Flush aortography – no role Provocative measures - vasodilators, heparin or

thrombolytic agents Techniques – vasopressin infusion or superselective

embolization Risks - Hematoma, arterial thrombosis, contrast reaction,

acute renal failure and complications related to therapy

True statement for the management of diverticulitis

a) Elective sigmoidectomy should be performed in young patients after one episode of diverticulitis to prevent recurrence b) Elective sigmoidectomy should be performed in patients > 50 years after two episodes of diverticulitis to prevent complications c) Elective sigmoidectomy is recommended after single attack of diverticulitis in immunocompromised patients d) Need for a colostomy to be fashioned increases with the increase in the attacks of diverticulitis Key – c

Elective sigmoidectomy should be performed in young patients

after one episode of diverticulitis was the earlier recommendation however recent studies do not it. Elective sigmoidectomy should be performed in patients > 50 years after two episodes of diverticulitis to prevent complications was the earlier recommendation which is not universally accepted. Need for a colostomy to be fashioned is highest with the first attack of diverticulitis. Elective sigmoidectomy after a single attack of diverticulitis should be considered in immunocompromised patients since these patients have diminished ability to combat an infectious insult.

Most common cause of colovesical fistula A) Diverticulitis B) Colonic cancer C) Bladder cancer D) Crohn’s disease Key – a

Right sided diverticula  

Common in Asia Usually mild and respond to medical therapy

Thorsen and Ternent classification    

Grade I - discrete, inflamed diverticulum. Grade II - simple cecal wall mass. Grade III - localized abscess or fistula. Grade IV -peritonitis (purulent or feculent).

Grade I/II – medical therapy or diverticulectomy +/-

appendectomy III/IV - resection

Giant diverticula   

Due to ball valve mechanism Majority asymptomatic Treatment in all cases – resection preferred over diverticulectomy

Diverticulitis with small pericolic/pelvic abscess –

After PCD resection in same ission Ureteral stents – decrease operative time not ureteral injury

All are risk factors for malignancy in ulcerative

colitis EXCEPT A) Duration of colitis B) Extent of colonic involvement C) Associated primary sclerosing cholangitis D) Younger age at onset of disease Key – d

Carcinoma in UC    

Evenly distributed throughout the colon More likely to be mucinous and poorly differentiated Higher likelihood of synchronous tumors No significant differences between sporadic and UC-related CRC with respect to prognosis.

UC with rectal tumor    

Upper third – IPAA can be done Middle and lower third -IPAA contraindicated Dysplasia in rectum (even lower third) - IPAA can be done No stapled anastomosis. Anorectal mucosectomy must

All are true statements regarding Dysplasia associated

with lesion or mass (DALM) in ulcerative colitis EXCEPT A) Associated with higher incidence of malignancy compared to high grade dysplasia B) Flat dysplasia more common than polypoid dysplasia C) DALM is not an absolute indication for proctocolectomy D) Polypoid dyplasia can be managed with endoscopic polypectomy Key - b

 Recent studies suggest that certain polypoid dysplastic lesions can be

managed via endoscopic polypectomy.  Prerequisite for endoscopic management - Lesion is well defined and

amenable to endoscopic polypectomy, and if biopsies of the flat mucosa immediately surrounding the polypectomy site do not demonstrate dysplastic change.  For lesions that are not amenable to endoscopic polypectomy or have

surrounding dysplasia, colectomy is recommended.  Approximately 25% of carcinomas in patients with ulcerative colitis are

not associated with dysplasia elsewhere in the colon

All are true statements regarding toxic megacolon in

ulcerative colitis EXCEPT a) Colonoscopy is contraindicated b) Gastrografin enema is contrainicated c) Steroids are contraindicated d) Antibiotics are routinely indicated as part of conservative treatment regime Ans - c

Criteria for diagnosis of toxic megacolon  



Radiological - colonic diameter >5.5 cm on plain films presence of any three of the following - fever higher than 38.5° C, tachycardia (>120 beats/min), leukocytosis (>10,500 cells), and anemia (hemoglobin <60% of normal) one of the following - dehydration, mental changes, electrolyte disturbances, or hypotension

Acute transmural inflammation Empirical treatment with oral vancomycin should be considered until

stool is confirmed negative for Clostridium difficile toxin. True love regimen for acute severe colitis  



NPO. Intravenous therapy.-At least 3 litres of fluid per day, potassium supplements, prednisolone, tetracycline 250 mg. four times a day Via rectum.-A rectal drip of 100 mg. hydrocortisone succinate sodium in approximately 120 ml. saline twice daily.

Definitions in UC Extent of disease

Severity of disease

Definitions in UC Steroid-refractory colitis 

Patients who have active disease despite prednisolone up to 0.75 mg/kg/day over a period of 4 weeks.

Steroid-dependent colitis 



i) unable to reduce steroids below the equivalent of prednisolone 10 mg/day within 3 months of starting steroids,without recurrent active disease, or ii) who have a relapse within 3 months of stopping steroids.

Remission 

combination of clinical parameters (stool frequency ≤3/day with no bleeding) and normal or quiescent mucosa at endoscopy

Pattern of relapse 

infrequent (≤1/year), frequent (≥2 relapses/ year), or continuous (persistent symptoms of active UC without a period of remission)

UC - facts Appendicectomy for histology proven appendicitis has been

shown to provide some protection against subsequently developing UC and in reducing its severity if performed for ‘true’ appendicitis at a younger age The use of non-selective NSAIDs is associated with increased risk for exacerbating UC Backwash ileitis –  

 

20% with pancolitis should be in continuity with colonic inflammation and the lesions in the caecum should show a similar, or greater degree of active inflammation. Pouch not contraindicated Focal, isolated ileal erosions, mucous gland metaplasia or patchy oedema with mild active inflammation are features suggestive of Crohn's disease

UC – histological features Paneth cell metaplasia 



Paneth cells are normally extremely uncommon in the colon distal to the splenic lexure The presence of Paneth cells in the distal colon termed as Paneth cell metaplasia

Basal plasmacytosis 



defined as presence of plasma cells around (deep part of the lamina propria) or below the crypts (subcryptal) At the initial onset has a high predictive value for the diagnosis of IBD

A diagnosis of established ulcerative colitis is based upon the

combination of:   

Basal plasmacytosis Heavy, diffuse transmucosal lamina propria cell increase and Widespread mucosal or crypt architectural distortion

All are true statement regarding colonic stricture in

ulcerative colitis EXCEPT A) Occur in 5-12% of patients with chronic ulcerative colitis B) Majority of the strictures are malignant, hence multiple biopsy need to be done C) Stricture distal to splenic flexure is more likely to be benign D) These strictures can cause large bowel obstruction Ans - B

Strictures in UC Although these strictures are most often benign,

caused by hypertrophy of the muscularis, cancer must be excluded Important features suggestive of malignant strictures: 1. Appearance later in the course of ulcerative colitis (60% after 20 years versus 0% before 10 years) 2. Location proximal to the splenic flexure (86% malignant) 3. Large bowel obstruction caused by the stricture

Ideal length of pouch in a patient with ulcerative

colitis planned for restorative proctocolectomy is A) 5-10cm B) 10-15cm C) 15-20cm D) 30cm Ans - B

Preferred pouch following IPAA – J pouch J pouch introduced by utsunomiya S pouch when difficult to mobilise terminal ileum Diasadv with W pouch – requires hand suturing and not possible in

narrow pelvis Efferent limb in S pouch less than 4cm to avoid evacuation disturbances Pouch reach is typically assessed by using the inferior aspect (or base) of the symphysis pubis as the yardstick

Steps if the pouch reach is inadequate 





 

Anterior and posterior horizontal relaxing mesenteric incision – gains 2 cm Division of two or three smaller ileal mesenteric vessels between the primary and secondary arcades - 2–5 cm of extra length (Burnstein) Preservation of the right branch of the middle colic artery and the marginal artery of the right colon and caecum with division of the right colic and ileocolic arteries at their origin and the superiormesenteric artery trunk at its distal third (Goes) – 10-11cm extra length Interposition vein graft to the superior mesenteric artery A stapled anastomosis to the upper anal canal requires 2 cm less reach than anastomosis after mucosectomy with hand-sewn anastomosis to the dentate line

Goes technique

Interposition graft

All are true statements regarding the effect of IPAA

on female reproductive health EXCEPT a) Fertility is adversely affected b) Increased incidence of dyspareunia c) Fecundity adversely affected d) Vaginal delivery is safe Key – c

Effect of pouch on reproductive health Females     

Pelvic adhesions - result in dyspareunia No change in menstrual cycle Vaginal delivery do not affect pouch function During pregnancy increased frequency of stools Fertility adversely affected because of pelvic adhesions but not fecundity

Males   

Impotence Retrograde ejaculation Overall improvement in sexual function

Most common cause for pouch failure in patients with UC a) Pelvic sepsis b) Anastomotic stricture c) Pouch ischemia d) Pouchitis )Key – a

Causes for pouch failure     

pelvic sepsis or fistula (35.5%), pouch ischemia (19.3%) Anastomotic stricture (16.1%) Pouchitis (16.1%). Crohn’s disease (12.9%)

Pouch salvage techniques  

Inversion followed by 180 degree forward and axial rotation Jejunal pouch and ileal interposition – used when short ileal mesentry does not allow the first procedure

True statement regarding pouchitis after IPAA for

ulcerative colitis A) frequency increases with time after surgery  B) It is defined as pouchitis disease activity index score of

more than 5  C) Sulfate reducing bacteria a facultative anaerobes colonise the pouch and are implicated in pathogenesis  D)Rifaximin more effective than ciprofloxacin for the treatment Key - a

Pouchitis 



   

Defined as pouchitis disease activity index score greater than 7 points. If less than 7 irritable pouch syndrome Pathogenesis – microbial imbalance & recurrence of IBD – basis for use of antibiotics & 5-ASA products Risk – maximum within first 6 months after ileostomy closure Risk increase for next 11/2 – 3 years Levels off around 4 years Cumulative risk increase significantly as followup approaches 10 years

All are treatment options for ulcerative

proctitisEXCEPT A) Oral mesalamine B) Steroid enema C) Proctectomy with restoration D) Restorative proctocolectomy

Key – c.

True statement regarding adenoma carcinoma sequence in

hereditary colorectal cancer A) Tumor initiation normal in FAP B) Tumor progression accelerated in FAP C) Tumor initiation accelerated in HNPCC D) Tumor progression accelerated in HNPCC Key – d

Most common site of carcinoma in FAP – left colon

All are true statements regarding Desmoids in

Familial adenomatous polyposis coli EXCEPT A) Second most common cause of mortality B) Common in females C) Surgery is the first line of therapy D) Raloxifene is used for treatment Key - c

Treatment of desmoid Begin with NSAIDs such as sulindac (150 mg twice per day) as first-line therapy.  If the tumor does not respond or progresses following 6 or more months of therapy, an antiestrogen such as tamoxifen (starting at 30 mg per day, witha slow increase up to 120 mg per day) or raloxifene (60 mg twice a day) may be added.  If the tumor responds, therapy can be gradually withdrawn over 6 months.  Cytotoxicchemotherapy with a doxorubicin-based regimens hould be reserved for extensive or life-threatening tumors that do not respond to noncytotoxic pharmacologic regimens and are not amenable to surgery.  Surgery should be reserved for localized desmoids of the limbs or abdominal wall or intraabdominal desmoids causing significant symptoms or complications 

According to Haggits criteria for level of invasion, a

carcinoma in a pedunculated polyp which extends beyond the epthelium into muscularis mucosae but restricted to head of polyp is classified as A) Level 0 B) Level 1 C) Level 2 D) Level 3 Key – a

All the following colonic polyps are benign EXCEPT

A) Juvenile polyps B) Hamartomatous polyps with PeutzJegher syndrome C) Serrated polyps D) Hyperplastic polyp Key - c.

Gardner’s syndrome characterized by A) Polyposis coli, ca thyroid and skin tumors B) Polyposis in jejunum, pituitary adenoma and skin

tumors C) Polyposis coli, osteomas, epidermal inclusion cysts and fibrous tumours in skin D) Polyposis of GIT, cholangiocarcinoma and skin tumour. Key - c

PeutzJegher syndrome is characterized by mutation of A) Chromosome 18 B) Chromosome 23 C) Chromosome 19 D) Chromosome 20 Key - C.

.

Screening test recommended for a family with FAP A) Colonoscopy B) Sigmoidoscopy C) Screening for APC gene D) DCC gene analysis. Key - B.

Screening for average risk patients for colon cancer

include all except A) FOBT annually B) Double contrast barium enema every 5 yr. C) Colonoscopy every 5 yrs. D) Flexible sigmoidoscopy every 5 yrs. Key - C.

FOBT - guaiac Qualitative test Rely on the oxidative conversion of a colorless

compound to a colored one in the presence of the pseudoperoxidase activity of hemoglobin (heme) Guaiac-impregnated paper and developing solutions (hydrogen peroxide in denatured alcohol) After applying the feces, one or two drops of hydrogen peroxide are then dripped on to the other side of the film, and it is observed for a rapid blue color change. Alpha-guaiaconic acid to a blue colored quinone

FOBT - guaiac Reason for false positive results   





Exogenous peroxidase activity Red meat (nonhuman hemoglobin) Uncooked fruits and vegetables (vegetable peroxidase: e.g., broccoli, turnip, cantaloupe, cauliflower, radish) Any source of GI blood loss (e.g., epistaxis, gingival bleeding, upper GI tract pathology, hemorrhoids) Certain medications (e.g., iron supplements, vitamin C, aspirin and other NSAIDs)

False negative results    

Storage of slides for a prolonged period Degradation of hemoglobin by colonic bacteria Ascorbic acid (vitamin C) ingestion Improper sampling or developing

Fecal immunochemical test Specific antibodies to detect human globin Not affected by diet or drugs Can differntiate small bowel from large bowel source According to guidelines of the American College of

Gastroenterology, "Annual fecal immunochemical testing is the preferred colorectal cancer detection test

Best treatment option for FAP with cancer in

sigmoid colon A) Total colectomy with IPAA without covering ileostomy B) Total colectomy with IPAA with covering ileostomy C)Subtotal colectomy followed by completion proctectomy with IPAA D) Subtotal colectomy with ileorectal anastomosis Key - c

IPAA in FAP special situations Whenever adjuvant therapy is required – preferably

pouch reconstruction is avoided Patients with desmoid pouch not possible Desmoids increase pouch related complications Young females – total colectomy with IRA followed by completion proctectomy with IPAA once family is completed

All are true statements regarding MYH gene associated

polyposis EXCEPT MYH gene responsible for base excision repair MYH gene mutation results in increased chance of APC gene mutation Number of polyps in affected individuals similar to FAP patients Affected individuals should be counselled regarding family planning since offsprings are at increased risk of developing this syndrome Key – d

Patients with MYH gene associated polyposis need to

be distinguished from those with FAP or AFAP because it implies increased risk in siblings, rather than offspring.

Which of the following hamartamatous polyposis

syndrome is NOT associated with increased risk of colorectal malignancy a) Turcot’s syndrome b) Cowden’s syndrome c)Juvenile polyposis syndrome d) PeutzJegher’s syndrome Key – b

Complete mesocolic excision (CME) of colon cancer Similar to TME concept of rectal cancer 3 components 





The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area . The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction

CME extent Caecum and proximal ascending colon 

Right hemi-colectomy with right branch of MCA and mesenteric lymph node dissection on the right side of MCA. Usually, the ICA is ligated at the level of the SMV but if suspicion exists of proximal lymph node metastases at the root of ICA, the resection may be carried to this level.

Distal ascending colon 

Right hemi-colectomy with right branch of MCA.

Right flexure and right transverse colon 

Extended right hemi-colectomy including MCA with tension-free anastomosis to the left. Some advocate resection of lymph nodes in the lateral 10 cm of the right gastro-epiploic vascular curvature, the sub-pyloric, and lymph nodes over the pancreatic head.

CME extent Transverse colon 



Resection of the transverse colon and MCA. If the resection is carried beyond the flexures, an anastomosis placed on the right may be considered. It is essential to avoid tension. Some may resect the left gastro-epiploic arcade if the tumour is situated to the left of the MCA and nodes along the inferior aspect of the left pancreas

Descending colon 

Left hemi-colectomy to origin of LCA, first sigmoid branch if tumour is quite distal, and left branch of MCA. If IMA is ligated, sigmoid resection is necessary.

Sigmoid colon 

Sigmoid resection with ligation of IMA about 1 cm from aorta

Stage II colon cancer with high risk features for

considering adjuvant chemotherapy include all of the following EXCEPT A) Increased preoperative CEA B) Presenting as complications C) High risk histology D) high levels of MSI Key - D  Absence of high levels of MSI, 18 q deletion and high S phase fraction are other risk factors.

True statement regarding CEA in colon cancer A) No correlation between CEA levels and metastatic

disease B) To assess completeness of resection CEA should be checked 2 weeks after surgery C) Even If preoperative CEA is not elevated CEA should be used for follow up D) None of the above Key - c

All are true statements regarding Adult Hirschprung

disease EXCEPT A) Common in males B) Usually a short segment disease C) Acetylcholinesterase staining typically shows decreased brown stained nerve fibres D)Rectoanalinhibitory reflex is absent Key – c

Acetylcholinesterase staining of the submucosa and

lamina propria reveals an increased number of large brown-stained nerve fibers and is considered 99% accurate in establishing the diagnosis.