MCH Questions in colon
Q 21 Least useful investigation in a pt with recurrent Lower GI bleed, multiple upper and lower GI endoscopies negative
b) Double balloon enteroscopy
c) Capsule endoscopy
d) Push endoscopy
Q22) Regarding colonic volvulus all are true except
a) Sigmoid volvulus without gangrene – colonoscopic decompression is the treatment of choice
b) Caecal bascule has high chance of gangrene due to torsion of mesentry
c) Splenic flexure volvulus has better prognosis than transverse colon volvulus
d) Recurrence rate after detorsion of cecal volvulus is 10-20%
Q23) For most colonic interposition for esophageal reconstruction which artery is not ligated
b) Rt colic
c) Middle colic
d) Left colic
Q24 ) In Crohns disease activity index all are included except?
b) Abdominal pain
d) Extra intestinal symptoms
Q 25) All are poor prognostic factors in colonic polyp except?
a) Poorly diff in the head
b) Moderately differentiated polyp
c) Involving the stalk
d) Margins positive
Q26) Extra intestinal manifestation of Ulcerative Colitis not cured by surgery
d) Erythema nodosum
Q27 ) Management of Rectal cancer which is 6cm from dentate line. No Lymph Nodes . No metastasis. Treatment is ?
a) Anterior Resection
b) Abdomino Perineal Resection
c) Local excision
Q 28) Most common mutation in HNPCC is (AIIMS 2012)
a) MLH1 and MSH2
b) PMS2 and MLH1
c) MLH1 and MSH1
d) PMS2 and MSH2
Q29. True regarding CEA is
a) Low specificity
b) Falls after 1 week of surgery to baseline
c) Preoperative high value is good prognostic marker
d) Follow up, first test of CEA in 8-10 days followed by weekly tests thereafter
30. All are false about adenomatous polyposis syndrome except
A. 25% do not have family history
B. Attenuated FAP has less than 100 polyps and delayed onset (50-55 yrs)
C. More than 20 rectal polyps have to be operated as there is high risk of Carcinoma
D. Attenuated FAP don’t have extracolonic manifestations and carry APC mutation
Investigations in lower GI bleed should be specific and less time consuming
Small bowel enteroclysis, which uses a tube to infuse barium, methylcellulose, and air directly into the small bowel, yields better images than simple small bowel follow-through. Because the yield has been reported to be very low and the test is poorly tolerated, it is now rarely used.
Capsule endoscopy uses a small capsule with a video camera. capsule endoscopy is an excellent tool for the patient who is hemodynamically stable but continues to bleed, with reported success rates as high as 90% in identifying a small bowel pathology.
The hemodynamically stable patient should undergo small bowel enteroscopy. Usually performed with a pediatric colonoscope, it is referred to as push endoscopy. It can reach about 50 to 70 cm past the ligament of Treitz in most cases and permits endoscopic management of some lesions. Overall, push enteroscopy is successful in 40% of patients .
Double-balloon endoscopy is another technique gaining in popularity. Although technically difficult, this approach is capable of providing a complete examination of the small bowel. In expert hands, double-balloon enteroscopy can identify a bleeding source in 77% of cases with occult bleeding, with the yield increasing to over 85% if the endoscopy is per-formed within 1 month of an overt bleeding episode.The advantage of this technique is that as well as visualization, biopsies can be performed and therapeutic interventions undertaken.
To conclude investigations in lower GI bleed have to be specific and have high sensitivity also.
Endoscopic reduction of sigmoid volvulus should be attempted in patients without evidence of bowel necrosis or perforation. An abdominal radiograph should be obtained following endoscopic detorsion to confirm resolution of the volvulus.
A variant of cecal volvulus termed cecal bascule is a condition in which a mobile cecum folds interiorly and superiorly over a fixed ascending colon without rotation on the vascular pedicle. Although local ischemia and infarction have been reported, vascular embarrassment occurs less frequently.
23 d left colic artery
Left colon replacement of the esophagus - Blood supply is provided through the inferior mesenteric artery, the left colic artery, and the anastomotic branch connecting the middle colic artery. The middle colic artery is divided near its origin from the superior mesenteric artery.
For complete mobility of the hepatic flexure, hepatic flexure, the right colic vessels often must also be divided.
Short segment colon transposition- The most popular segment of colon to use for distal esophageal replacement is an isoperistaltic segment of the distal transverse colon or the descending left colon based on the ascending branch of the left colic artery.
Best colonic interposition graft is left hemi colon with isoperistaltic anastomosis. It is because of two reasons. First its blood supply is robust and dependable and 2nd because of the size match. Presence of marginal artery between left branch of middle colic artery and ascending branch of left colic artery is critical. Left hemi colon graft is completely based on left colic artery.
Middle colic artery is ligated. Right colic artery is also ligated. This is for left hemi colon graft.
The question states that transverse colon is used for colonic interposition. Short segment transverse colon grafts are based on middle colic artery.
Crohn disease activity index is a medical tool, which helps to quantify the symptoms and problems of Crohn's disease
It helps to quantify the disease
It helps to assess response to medical therapy
Crohn's disease activity index includes
- Number of liquid or soft stools per day for 7 days - X 2
- Abdominal pain graded from 0-3 based on severity each day for 7 days - X 5
- General well being assessed from 0-4 - X 7
- Presence of complications (extraintestinal manifestations) - X 20
- Taking diphenoxylate/loperamide/opiate/atropine for diarrhoea - maximum weightage- X 30
- Presence of an abdominal mass - X 10
- Hct of < 0.47 in men and <0.42 in women - X 6
- % of deviation from standard weight - X 12
- 25) b
Poor prognostic factors in a polyp aare
1. histologically poorly differentiated invasive carcinoma
2. cancer cells observed in the lymphovascular spaces, there is a more than a 10% chance of metastases
3. A pedunculated polyp with invasion to levels 1, 2, and 3 has a low risk for lymph node metastasis or local recurrence and complete excision of the polyp is adequate if the poor prognostic factors mentioned earlier are absent .
4. A sessile polyp containing invasive cancer has at least a 10% chance of metastasis to regional lymph nodes , but if the lesion is well or moderately differentiated, there is no lymphovascular invasion noted, and the lesion can be completely excised, the depth of invasion by the cancer may provide useful prognostic information.
There is a high risk for lymph node and distant metastases associated with sessile cancers in the rectum, and these lesions should be treated aggressively.
Arthritis, ankylosing spondylitis, erythema nodosum, and pyoderma gangrenosum typically improve or completely resolve after colectomy.
PSC occurs in 5% to 8% of patients with ulcerative colitis.
HLA-B8 or HLA-DR3 haplotype are 10 times more likely to develop PSC.
The risk for colon cancer in these patients is up to five times greater than in patients with ulcerative colitis alone. These tumors are more likely to arise proximal to the splenic flexure . Colectomy has no effect on the course of PSC.
27 ) a
Cancers 6 cm above dentate line are considered to be upper ectum. Patients with cancer of the upper part of the rectum or rectosigmoid are generally treated initially by surgical resection, and adjuvant therapy.
Sphincter-preserving resections of the rectum are referred to as anterior resection, low anterior resection (LAR), or low anterior resection with coloanal reconstruction.
In general, anterior resection refers to resection of the sigmoid or rectosigmoid . LAR is used to refer to anterior resection combined with complete clearance of the pelvic side walls. Anterior resection is excision of proximal rectum or rectosigmoid above the peritoneal reflection.
The term low anterior resection indicates that the operation entails resection of the rectum below the peritoneal reflection through an abdominal approach.
Local excision has is done for lesions which are T1 and upto 10 cm from the anal verge.
Lynch syndrome is an autosomal dominant familial Colo Rectal Cacner syndrome characterized by familial clustering of early age-of-onset CRC (average age, 40 to 48 years), as well as a variety of other cancers.
First two MMR genes to be identified were MSH2 and MLH1. Each of these proteins forms a heterodimer with so-called minor partners, MSH6 and PMS2.
In contrast to the chromosomal abnormalities associated with the classic adenoma-to-carcinoma sequence, the genetic changes associated with MMR mutations are more subtle. MLH1 is the gene most likely to be affected in this way in sporadic cases of MSI-H colon cancer . Microsatellite instability is of prognostic significance in colon cancer. Patients with MSI-H colorectal cancer have a better prognosis when compared to patients with microsatellite-stable tumors of similar stages.The absence of MMR proteins may also predict decreased responsiveness to 5-fluorouracil–based chemotherapy.
With a reference value of 5 ng/ml, the sensitivity of CEA was at 37% only for patients with colorectal carcinoma at Dukes B stage, 66.6% for patients at stage C, and 75% for patients at stage D. The specificities of the CEA for the cancers of the colon and rectum were at 76.98% with a reference value of 5 ng/ml and 86% with a reference value of 10 ng/ml
HIgh preop value - poor prognosis
Follow up after surgery is 6 monthly
The gene is expressed in 100% of patients with the mutation. Autosomal dominance results in expression in 50% of offspring. So choice a is false
Attenuated FAP is a milder form of classic familial adenomatous polyposis (FAP) and is characterized by fewer colon polyps (an average of 30) and a delay in the development of colon cancer (average age 50 to 55 years) (True)
AFAP is caused by mutations in the APC gene and is inherited in an autosomal dominant manner.