Colon, rectum, and Anus Flashcards
(34 cards)
A 74 year old man with biopsy proven rectal adenocarcinoma is undergoing a low anterior resection. Which layers must be stapled through when resecting the distal portion of resection specimen?
Mucosa, submucosa, longitudinal muscle layer, and circular muscle layer
- The wall of the colon and rextum are made of 5 separate layers: mucosa, submucosa, circular muscle layer, longitudinal muscle layer, and serosa
- The mid and lower rectum lack serosa
Which layer of the muscle joins together to form the internal anal sphincter
Circumferential muscle layer
- The inner circular layer joins to form the internal anal sphincter
- The subcutaneous, superficial, and deep external spincher surrounfs it
- the deep external anal sphincter is an extension of the puborectalis muscle
a 24 year old woman with medically refractory ulcerative colitis decides to undergo a total colectomy, During this procedurem where would it be most appropriate to look for the inferior mesenteric vein in order to ligate it?
The inferior mesenteric vein is often ligated at the inferior edge of the pancreas, just below where it joins with the splenic vein
- The Inferior mesenteric vein does not run with the inferior mesenteric artery. Instead, it travels cranially in the retroperitoneum over the psoas and then posterior to the pancreas to join the splenic vein
An anatomy class is dissecting out the rectum. What are the correct fascial arrangements that they will encounter?
- Presacral fascia
- seprates the rectum from the presacral venous plexus and the pelvic nerves
- Waldeyer fascia
- extends forward and downward and attaches to the fascia propria at the anorectaal junction
- Denovilliers fascia
- separates the rectum from the prostate and seminal vesicles in men and from the vagina in women
Intestinal Malrotaion
At the 6th week of gestation, the midgut herniates through the abdominal caviry, rotates 270 degrees COUNTERCLOCKWISE around the superior mesenteric artery and then travels to its resting place in the abdomen during the 10th week. Failite of the midgut to rotate and return during the 10th week results in intestinal malrotation
a 62 year old man has perforated diverticulitis and undergowes an emergent left hemicolectomy with a diverting loop ileostomy. If he has a high outout ileostomy and is at risk of diversion colitis, which fatty acids are not being absorbed?
Butyric acid and propionic acid
- Short chain fatty acids (acetic acid, butyric acid, and propionic acid) are produced by bacterial fermentation of dieatery carbohydrates and are important source of enery for the colonic mucosa and metabolism by colonocytes
- diversion colitis
- mucosal atrophy and inflammation
A 58 year old mother of 10 suffers from fecal incontinence. Usually defecation occurs by increased intraabdominal pressure via the valsalva maneuver, increased rectal contraction and relaxation of the puborectalis muscle, which forms a “sling” around the distal rectum, forming a relatively acute angle. straighthens, allowing downward force to be applied along the axis of the rectum and and anal, and opening of the anal canal. A dysfunction at which point of this pathway can lead to fecal incontinence
Injury to the puborectalis
- impaired continence may result from poor rectal compliance, injury to the internal and/or external sphincter or puborectalis, or nerve damage or neuropathy
A healthy 48 year old physician with no family history of cancer and who strictly adheres to a high protein, high fiber diet, exercises five times per week for 50 minutes and takes vitamin C supplements daily performs a fecal occult test, and tests postive, should she have any further colon screening?
Yes, all positive FOBT requires further further investigation with a colonoscopy
- FOBT is a nonspecific test
- peroxidase contained in the hemoglobin
- Red meat, some fruits, and vegetables, and vit C will produce a false positive result
A 22 year old college student presents to the clinic with a history of intermittent diarrhea for the past 5 days. after returning to Mexico. On further questioningm she has had rpevious episodes if diarrhea for the past 2 years, unrelated to travel, After a physical examination, what are the appropriate tests that should be ordered to appropriately work up this patient?
- Stool and wet mount and stool culture
- Sigmoidoscopy and colonoscopy, but only if no peritoneal signs on PE
- Add sudan red to stool
- malabsorption
A 76 year old man undergoes an emergent sigmoidectomy for a perforated colon mass, The surgeon performs a Hartmann procedure and brings up a colostomy, In an emergency setteing, where is the most appropriate location to seat a colostomy?
Above the beltline, within the rectus abdominis muscle, and away from the costal margin
A previously healthy 46 year old woman with a history of rectal adenocarcinoma first discovered on colonoscopy 1 year ago who is status post LAR with a diverting loop ileostomy resturns to the clinic 3 months after her LAR for a preoperative appointment for her ileostomy reversal. Over the past 3 months she has had good ilesotomy output as well as occasional loose stools per rectum. What workup does she need to have prior to ileostomy reversal?
Fleximble sigmoidoscopy or contrast enema to check for patency
- Flexible sigmoidoscopy and a contrast enema are reommended prior to closure to ensure than the anastomosis has not leaked and is patent
a 75 year old woman undergoes a right hemicolectomy and end ileostomy for right sided perforated diveriticulitis, What is the most concerning adverse outcome in the short term of this procedure and will require revision?
Stoma necrosis below the level of the fascia
- stoma necrosis may occur in the early post operative period
- skeletonizing the distal small bowel and/or creating an overly tight fascial defect
- necrosis below the level of the fascia requires surgical revision
- Stomal retratcion may occur early or late and may be exacerbated by obesity
A 19 year old man with medically refractory ulcerative colitis undergoes a total colectomy with J-pouch creation. What are some of the late complication of ileal pouch anal reconstruction?
- More than 8 bowel movements per day
- Nocturnal incontinence
- Pouchitis
- Small bowel obstruction
A 50 year old woman who underwent a total colectomy with ileal pouch anal reconstruction 5 years ago present to the emergency room with diarrhea, fever, 2 weeks of malaise, and severe abdominal pian. What is most appropriate differential diagnosis?
Bacterial or viral infection, undiagnosed Crohn disease and pouchitis
- Pouchitis
- inflamamtory condition that affects both ileoanal and continent ileostomy reservoirs
- 30 to 55%
- Increased diarrhea, hematochezia, abdominal pain, feer, and malaise
- Diagnosis: endocopy with biospies.
A 68 year old man is undergoing a right hemicolectomy for a cecal mass. hea sks what the current research has shown about decreasing postoperative infection after his procedure. When should antibiotics always be used for this procedue?
PArenteral antibiotic prophylaxis at the time of surgery before the skin incision is made
A 2 2year old woman present sto the clinic with a 3 year history of bloody diarhhea, abdominal pain, and anorectal distulas. Her father had similar symptoms during his 20s and had multiple abdominal surgeries. What is the percentage of patients with this disease who have family members with the same disease?
10-30%
A 25 year olf man is undergoing workup to determine if he has ulcerative colitism crohn disease or inderminate colitis. What is the diagnostic findings would indicate that he has crohn disease?
Muscoal ulcerations, noncaseating granulomas, fibrosis, strictures, and fistulas in the colon with deep serpigonous ulcers
- UC
- mucosa may be atrophoc and crypt abscesses are common
- friable mucosa
- multiple inflammatory pseudopolyps
- continuous involvement of the rectum and colon
What structures are most likely to be site of extracolonic disease in IBD?
Liver, biliary tree, joints, skin, eyes
- Liver - fatty infiltration (40 to 50%)
- Primary sclerosinh cholangitis - intra and extraheaptic bile duct strictures
- Pericholangitis
- Arthritis
- Erythema nodusum (5 to 15%)
- pyoderma gangrenosum
- ocular lesions (uveitis, iritis, episcleritis, conjunctivitis)
An 18 year old woman is udnergoing workup to determine if she has ulcerative colitis, Crohn disease, or indeterminate colitis. What diagnostic findings would indicate that she has ulcerative colitis?
Atrophic mucosa, crypt abscesses, inflammatory pseudopolyps, scarred and shortened colon, continuous involvement of rectum and colon
The goal of medical therapy for IBD are to decrease inflammation and alleviate sx. Mild to moderate flares are treated in the clinic and more severe symptoms may require hospitalization. What is the first line therapy for IBD in the outpatient setting?
Salicylates
A thin and ill appearing 26 year old man presents to the emergency deparment with feversm chikksm severe abdominal pain, and rigid abdomen, While doing a history and OEm it is noted that he has a history of ulcerative colitis, What would be indications that stoma creation would be more appropriate than a primary anastomosis?
In extremely malnourished patients, especially those who are also being treated with corticosteroids, creation of a stoma is oftern safer than a primary anastomosis
- serum albumin
- prealbumin
- transferrin
A 24 year old woman present to the ED with fever, severe abdominal pain, with guarding on palpation, and a history of 5 day of bloody stools. She has a history of UC. what are the indications for ulcerative colitis
- Hemorrhage with continued decrease in HCT levels in spite of blood transfusion
- Hemodynamic instability requiring transfer to the ICu with decline in status over 48 hour period after admission
- Severe abdominal pain and diarrhea that does not respond to bowel rest, hydration and parenteral corticosteroids
- Cecum measured at 9 cm in diameter on CT
A 55 year old woman with a history of long standing crohn disease presents to the clinic with a 1 month history of abdominal pain and a new area of induration, fluctuance, adn foul smelling drainage from a former midline incision. What are the msot common indications for surgery for crohn disease?
Intestinal fistula or abscess (30-38%)
Obstruction (35-37%)
A 23 year old man present sto the clnic with severe pain on defecation that began 2 months ago. He has tried conservative management at home with sitz baths but his pain has become so severe that he has start to restrict how much he eats to prevent having bowel movement, On rectal examination, a fissure is found. what would indicate that this fissure is from Crohn disease?
Deep, and broad ulcer located in the lateral position
- The most common perinanal lesions in crohn disease are skin tags that are minimally symptomatic
