Editing Intestinal Segments and Urinary Diversion (section)

== Answers ==

# List 5 differences between the ileum and jejunum
#* Ileum: more distal, smaller lumen, multiple arterial arcades, smaller arcade vessels, thicker mesentery
#* Jejunum: more proximal, larger lumen, single arterial arcades, larger arcade vessels, thinner mesentery
# What is the safe maximum distance of bowel that will survive away from a straight vessel?
#* 8cm
# What segments of bowel should be avoided in a patient with prior pelvic radiation?
## Last 2 inches of ileum
## 5 feet of small bowel beginning 6 feet from ligament of Treitz
# What are potential weak points in blood supply to the colon?
## Between middle colic and left colic
## Between middle colic and right colic
## Between sigmoidal and superior rectal (Sudeck point)
# What are potential advantages of a stomach conduit?
## Electrolyte imbalances rarely occur
## Not associated with malabsorption; may be preferred option in patients with short bowel syndrome
## Not usually in field of radiation, may be preferred option in patients with previous pelvic radiation
## Produces less mucus
## Acidic pH reduces bacterial colonization
# Which bacterial flora are found in the bowel?
#* Aerobic: E. coli and enterococcus
#* Anaerobic: bacteroides and clostridium
# What is the bacterial concentration in the jejunum? Distal ileum? Ascending colon? Descending colon?
#* The bacterial concentration ranges from 10-105 organisms per gram of fecal content in the jejunum, 105-107 in the distal ileum, 106 -108 in the ascending colon, and 1010-1012 in the descending colon.
# What is the goal of mechanical vs. antibiotic bowel regimen?
#* Mechanical: reduce bacterial load
#* Antibiotic: reduce bacterial concentration
# What are contraindications to whole-gut irrigation?
## Obstructed bowel
## CHF
## Unstable cardiovascular system
## Cirrhosis
## Severe renal disease
# What are the principles of intestinal anastomoses
## Adequate exposure
## Adequate blood supply
## Prevention of local spillage or enteric contents
## Serosal apposition (watertight, without tension)
## Don’t tie suture so tightly that the tissue is strangulated
## Realignment of the mesentery of the two segments of bowel to be joined
# List contraindications to use of ileum for conduit.
## Short bowel syndrome
## Inflammatory bowel disease
## History of extensive pelvic radiation
# List contraindications to use of transverse, sigmoid, and ileocecal conduits.
## Presence of inflammatory large bowel disease
## Severe chronic diarrhea
# Which segment of bowel is associated with the highest rates of post-operative bowel obstruction?
#* Ileum
# What are risk factors for bowel anastamosis breakdown?
## Poor blood supply
## Local fecal spillage
## Drain placed near anastamosis
## Radiation
# List 3 different techniques of anastomosing the ureter to the small bowel
## Bricker – end to side
## Wallace – end to end
## LeDuc – laid down on ileal track
# Which technique of anastomosing the ureter to the small bowel has the lowest complication rates?
#* Wallace
# List complications associated with ureteroenteric anasmoses.
#* Leakage
#* Stenosis
#* Renal insufficiency
#* Reflux in those that were constructed with anti-reflux method
#* Acute pyelonephritis
# List the metabolic complications of urinary intestinal diversion
#* LSD ORGASMIC
#* Lytes, Sensorium altered, Drug metabolism alterted, Osteomalacia, Renal function deterioration, growth suppression, acidosis/alkalosis, stones, malabsorption, infection, cancer
# Which bowel segment used in urinary diversion is associated with elevated aldosterone? Elevated renin?
#* Elevated aldosterone: stomach
#* Elevated renin: jejunum
# What is the treatment of hypochloremic metabolic acidosis in a patient with an ileal conduit?
#* Sodium bicarb; can be substituted for potassium citrate if cardiac or renal disease preclude sodium or potassium substitution beneficial
# What renal function parameters are recommended for patients undergoing continent diversion?
## eGFR > 45 (AUA MIBC Guidelines)
## Minimal protein uria
## Urine pH ≤ pH of 5.8 after an ammonium chloride load
## Can achieve urine osmolality ≥ 600 mOsm/kg in response to water deprivation
# List 3 mechanisms of diarrhea associated with ileal conduit
## Bile salt malabsorption
## Fat malabsorption
## Loss of ileocecal valve
# What may deficiency may result from malabsorption when using jejunum for urinary diversion?
#* Fat, calcium, folic acid
# What are the electrolyte derangements associated with:
#* Ileal conduit: hyperchloremic, hypokalemic metabolic acidosis
#* Jejunal conduit: hypochloremic, hyperkalemic metabolic acidosis
#* Stomach conduit: hypochloremic, hypokalemic metabolic alkalosis
# When should treatment of asymptomatic bacteruria in a urinary diversion be considered?
#* Pure proteus or pseudomonas in culture
# What is the expected histology of a bladder cancer associated with urinary diversion?
#* Adenocarcinoma