Lower GI Surgery Flashcards
What is the most common cause of small bowel obstruction?
The most common causes are adhesions from a previous surgery and hernias.
How does a small bowel obstruction present?
Presents as colicky abdominal pain, nausea/vomiting, and constipation
How do you manage and treat a small bowel obstruction?
Get a KUB, diagnosis is by air fluid levels and dilated loops; tx NPO, NG suction, IVF, and initially observation
What is the electrolyte imbalance caused by small bowel obstruction?
Hypokalemic hypochloremic metabolic alkalosis due to emesis
What does bloody diarrhea and a small bowel obstruction indicate?
Obstructive tumor or ischemic bowel
dx: sigmoidoscopy –> observe if mucosal, resection if full thickness
What does a SBO + flatus indicate?
Indicates partial SBO since gas can get through, more likely to resolve without surgery
What does SBO + diarrhea indicate?
Indicates partial SBO due to fecal impaction and severe constipation
What does SBO + inguinal hernia indicate?
Requires urgent hernia repair to relieve strangulation
What does SBO with melanoma indicate?
Melanoma is the most common tumor that metastasizes to the intestine, surgery is indicated since these don’t resolve spontaneously
What does SBO + peritonitis present as?
Presents as rebound tenderness, increased WBC, fever, or metabolic acidosis due to necrotic bowel; indicated for ex lap
How do you manage SBO + adhesions?
Indicated for ex lap –> lysis of adhesions
What causes SBO and closed loop obstruction?
Usually due to an adhesive band occluding two segments of bowel; indicated for x lap –> lysis of adhesions, resection of any dead bowel, and “second look” operation if bowel viability is indeterminate
What does SBO + pneumoperiotneum indicate?
Indicates perforation due to ischemic or overdistended bowel; indicated for ex lap and dead bowel resection
What are you at risk for if there is a nicked bowel during LOA?
Small hole –> primary repair
Large or multiple holes –> bowel resection; high risk of leakage or EC fistula formation
What do you do if you are uncertain about an SBO?
Get an upper GI series with small bowel follow-through, barium contrast will stop at site of obstruction if SBO exists
How does mesenteric ischemia present?
Presents as postprandial abdominal pain, weight loss, SBO, and multiple abdominal bruits usually due to atherosclerosis of celiac trunk or SMA
How do you manage mesenteric ischemia?
Dx by mesenteric angiogram
Tx revascularization
follow up with aspirin and evaluation for other atherosclerotic diseases
How does mesenteric ischemia + peritonitis present?
Presents as rebound tenderness, increased WBC, fever, or metabolic acidosis due to necrotic bowel; ex lap indicated
What does mesenteric ischemia with afib indicate?
Indicates emboli shooting from left atrium to celiac trunk or SMA
What does mesenteric ischemia with an increased hct indicate?
Polycythemia due to severe dehydration
Requires IV fluid resuscitation
What does mesenteric ischemia + CHF indicate?
Ischemia may be secondary to low-flow, nonocclusive state; indicated for mesenteric vasodilation and improve cardiac output
How can an aortic dissection cause mesenteric ischemia?
The dissected aorta can occlude mesenteric vessels;
dx angiography
tx surgical repair
What are you concerned about with mesenteric ischemia with a decrease in blood pressure?
Either ischemic bowel causing septic shock or hypotension causing low-flow, non occlusive ischemia
How do you treat left colon necrosis?
Bowel resection –> anastomosis
If stable, otherwise colostomy and Hartmann pouch
How do you treat long segment necrosis?
Bowel resection –> small bowel syndrome requiring chronic TPN or transplant
How do you treat short segment necrosis?
Bowel resection –> anastomosis, “second look” operation if bowel viability is indeterminate
What does small punctate necroses indicate and how do you treat it?
Indicates multiple small emboli or low-flow state
Tx bowel resection –> anastomosis, “second look” operation if bowel viability is indeterminate
How do you treat bowel ischemia without necrosis?
Try to revascularize the bowel by removing or bypassing the occlusion
How does inflammatory bowel disease present?
Crohn’s disease and UC present as crampy abdominal pain, bloody diarrhea, and recent weight loss
How do you manage IBD?
Colonoscopy to determine if it’s UC, Crohn’s, or something else
Abdominal CT scan for confirmation
What is Crohn’s disease?
Inflammatory disease involving full GI tract with skip lesions (terminal ileum is the most common site)
bx shows full thickness + noncaseating granulomas + creeping fat
dx terminal ileum string sign on CT scan
How do you manage Crohn’s disease?
IV steroids and 5-ASA for acute flare-ups
What causes SBO in Crohn’s? How do you manage it?
Due to stenotic terminal ileum
Manage with NPO, TPN, and observation–> if it fails to resolve, surgical stricturoplasty is indicated
How do you treat Crohn’s with rectal disease?
Rare, indicated for subtotal colectomy and ileostomy
What is ulcerative colitis?
Inflammatory disease involving the rectum and continuous proximal extension
bx shows mucosal involvement + crypt abscesses + pseudopolyps
dx lead pipe sign on CT scan
How do you manage UC?
IV steroids and 5-ASA for acute flare-ups, annual colonoscopy for possibility of cancer
How do you treat UC with severe dysplasia?
Total proctocolectomy, ileal pouch formation, and ileo-anal anastomosis; no further cancer surveillance needed
What is pouchitis? How do you treat it?
Presents as fever, bloody diarrhea, and pain on defecation s/p ileal pouch formation for UC
Tx: metronidazole
How does toxic megacolon present?
Presents as fever, bloody diarrhea, pain, and abdominal distention in a patient with UC
How do you manage toxic megacolon?
Get KUB for confirmation, then NPO, IVF, NG suction, IV steroids and abx
If it improves, then surgery is not necessary
Otherwise surgery is needed
What do you see if there is perforation of toxic megacolon?
Shows free air on upright CXR, indicated for total colectomy and ileostomy with Hartmann pouch
How does appendicitis present?
Presents as RLQ pain, low grade fever and leukocytosis; MCC is lymphoid hyperplasia
How do you manage appendicitis?
Get CT scan or U/S; if uncomplicated, the appendectomy if abscess (fever and increased WBC) --> perc drain, interval appendectomy
How does appendicitis present in children, the elderly, and in pregnant women?
Children: appendicitis more often ruptured appendix
Elderly: usually don’t have classic presentation of appendicitis, but rather vague abdominal complaints, sepsis, AMS, or FTT
Pregnancy: enlarged uterus can push appendix upwards –> RUQ pain, appendectomy can be performed safely
What is the differential for RLQ pain and dysuria?
Indicates appendicits, UTI, PID, gastroenteritis, or appendiceal abscess next to bladder
What is the likely cause of RLQ pain and BPH symptoms?
Bladder outlet obstruction due to an enlarged prostate, tx with Foley
What are the possible appendectomy findings?
Inflamed appendix, perforated appendix, normal appendix, inflamed cecum, fecalith, carcinoid tumor, other tumors
How do you manage an appendiceal carcinoid?
2 cm hemicolectomy
Can present with carcinoid syndrome due to liver metastasis
How does diverticulosis present?
Presents as LGIB, 85% stop spontaneously, may develop into diverticulitis
Presents like left-sided appendicitis, get CT scan and manage non-op if possible even with signs of LLQ peritonitis
What are the surgical indications of diverticulitis?
Uncontained perforation that presents as 4 quadrant peritonitis or pneumoperitoneum, occurs more than 4 times
Follow up with colonoscopy to confirm presence of diverticula and absence of cancer
What are the complications of diverticulitis?
Abscess, obstructions, fistula (pneumaturia or fecaluria)
How and when should you screen for colon cancer?
Anyone above 50 y/o should get yearly fecal occult blood test (flex sig and colonoscopy also used, but less commonly)
What are colon polyps? How do you manage them?
Tubular/pedunculated and have a stalk
Sessile/villous are flattened
Progression from polyp to cancer takes about 10 years
If these are dysplastic, then segmental colectomy
How do you diagnose colon cancer?
Left side obstructs, right side bleeds
“apple core” lesion on barium enema
Tx with colectomy unless stage IV, then palliative care only
What are the worrisome post-op complications of a colectomy?
Wound infection
Feculent leak : indicated anastomotic leak, get abd CT scan to check for undrained collection, then NPO/IVF
Feculent vomit: indicates either post-op ileus or mechanical obstruction, treat NPO?IVF and NG tube
Abscesses: CT scan, perc drain
Constipation: stricture or cancer recurrence, dx with colonoscopy
What is FAP? How is it treated?
Delta APC on chromosome 5p
autosomal dominant
presents as >100 polyps in colon
tx either total proctocolectomy or total abdominal colectomy + strip anal mucosa + ileoanal anastomosis
What is Gardner syndrome?
FAP + polyps in stomach (not premalignant) and duodenum (malignant)
FAP patients should get upper endoscopy and remove the duodenal polyps
What is HNPCC? How do you treat it?
Delta MLH or delta MSH mismatch repair genes
Leads to microsatellite instability
tx total abdominal colectomy + ileorectal anastomosis
How do you prevent recurrence of colon cancer?
Colonoscopy, CEA markers, CXR for lung metastasis, LFTs for liver metastasis
What is the first step in management of all anorectal disease?
Scope and rule out cancer
How do hemorrhoids present?
Present as blood streaks in stool and extreme pain (external)
Tx scope to rule out cancer, fiber/stool softeners
if it keeps bleeding, excision or banding
What do non healing hemorrhoids indicate?
anal canal cancer tx chemoradiation (5-FU) --> APR if it persists or recurs
What is LAR vs. APR?
LAR: low anterior resection (high in rectum)
APR: abdominoperineal resection (low in rectum)
How does anal cancer present? How do you treat it?
Anal cancer presentation is non-specific (bleeding, pain, drainage, itching) and requires biopsy
Small anal cancer: tx resection with negative margins
Large anal cancer: often mistaken as “non healing hemorrhoids” tx chemoradiation and APR if it persists or recurs
What is the common consequence of a perirectal abscess?
40% will develop a fistula, tx with fistulotomy
What is an anal fissure?
Presents as pain and blood with BM due to increased sphincter tone
tx with fiber/stool softeners
if it won’t heal, botox
recurring anal fissure is suggestive of Crohn’s
How does rectal prolapse present?
Rectal protrusion following defecation
Internal prolapse –> high fiber diet to normalize BM, external/bleeding prolapse –> rectopexy or LAR
What is melena?
Coffee ground blood in stool, usually UGIB but can also be from ascending colon
What is hematochezia?
BRBPR, can either UGIB or LGIB;
NG tube aspirate/lavage
LGIB if -blood/+bile
UGIB if +blood
What is UGIB?
GI bleeding proximal to Ligament of Treitz, management is EGD
What is LGIB?
GI bleeding distal to Ligament of Treitz, 85% stop spontaneously
MCC are AVM, diverticulosis, and colon cancer
How do you manage a LGIB?
Must localize site of bleeding with tagged RBCs or angiography; if not currently bleeding, get upper and lower endoscopy
What does LGIB indicated in kids?
Meckel’s diverticulum
Dx with technetium uptake into ectopic gastric mucosa
What are tagged RBCs and angiograms good for?
Tagged RBCs: sensitive for LGIB at 0.1 cc/min, but not specific for localizing site of LGIB
Angiogram: less sensitive for LGIB at 1.0 cc/min, but more specific for localizing site of LGIB, allows for smaller LGI resection in surgery if necessary
What is sigmoid volvulus?
Twisting of sigmoid colon around mesentery resulting in closed-loop obstruction; tx is “detorsing” the colon via rigid scope and rectal tube, then elective sigmoid colectomy
What is cecal volvulus?
Twisting of cecum; tx right colectomy since detorsion doesn’t work
What is Ogilvie’s syndrome?
Pseudoobstruction and massive colon dilation without mechanical obstruction
tx endoscopic decompression or neostigmine if >11 cm due to possibility of cecal perforation
