Conduits, Neobladders, and Metabolic Probs Flashcards
(30 cards)
What are the overall metabolic disturbances if the STOMACH is used as a conduit/reservoir?
Hypokalemic, hypochloremic, metabolic alkalosis
(low potassium, low chloride, HIGH pH)
- Only reservoir to cause alkalosis
- all ions are low
- loss of HCl out of urine, so low chloride.
What are the overall metabolic disturbances if the JEJUNUM is used as a conduit/reservoir?
Hyponatremic, hyperkalemic, hypochloremic, metabolic acidosis
(low sodium, HIGH potassium, low chloride, low pH)
*only reservoir with hyperkalemia
What are the overall metabolic disturbances if the ILEUM/COLON is used as a conduit/reservoir?
Hypokalemic, hyperchloremic, metabolic acidosis
**colon hypokalemia is much worse vs ileum
(low potassium, HIGH chloride, low pH
First line tx for metabolic disturbance of ILEAL/COLON reservoirs?
Potassium citrate, sodium citrate, or citric acid solution
- increases citrate, which moves into mitochondria during intracellular acidosis, allowing for pH to rise
- also helps with hypokalemia and stone prevention
Second line tx for metabolic disturbance of ILEAL/COLON reservoirs?
Chlorpromazine or nicotinic acid
- inhibits chloride transport, thus decreasing bicarbonate loss (treats the acidosis)
What are some of the general side effects of conduits?
- Diarrhea (mostly ileal/colon)
- due to irritating bile salts and emulsified fats, usually absorbed in the terminal ileum, reaching the colon
- tx with Cholestyramine, high fiber diet, loperamide - Hypocalcemia/osteomalacia
- due to metabolic acidosis (except in stomach reservoir) - B12 deficiency
- loss of intrinsic factor secretion (stomach) or B12 absorption (ileum)
- body has 3-5 years storage, so megaloblastic anemia/neurologic deficits take years - Elevated medication levels
- concerning meds: methrotrexate, phenytoin, lithium
Each reservoir/conduit has only ONE elevation and no other conduit shares it.
Name the elevated disturbance with stomach conduits?
HIGH pH (metabolic alkalosis)
Each reservoir/conduit has only ONE elevation and no other conduit shares it.
Name the elevated disturbance with jejunal conduits?
HIGH potassium
Each reservoir/conduit has only ONE elevation and no other conduit shares it.
Name the elevated disturbance with ileal/colon conduits?
HIGH chloride
Which conduit is the ONLY conduit with severe disturbances in sodium?
Jejunal (hyponatremia)
What are the 4 primary types of neobladders?
- Mainz pouch (ileocolic pouch)
* note there are 3 sub-types - Hautmann (W pouch from distal ileum)
- Ghoneim (Hautman with extramural tunnel for ureters)
- Studer (distal ileum ball with long afferent limb)
When making a Mainz pouch, division of which artery may be necessary to increase colon mobilization?
Why are you not worried that the remaining colon won’t infarct?
Division of the RIGHT COLIC will increase mobilization
The ARC OF DRUMMOND will maintain arterial supply to remaining colon
What are the 3 Mainz pouch subtypes
Mainz 1 = ileocecal reservoir with catherizable appendix
Mainz 2 = ureterosigmoidostomy
Mainz 3 = transverse colon
Avoid neobladders in patients with what general problems?
- Creatinine > 2
- Hepatic failure
- inflammatory bowel disease
- histologically proven cancer at prostate apex (males) or bladder neck (females)
- Lack of intellect or lack of physical capacity to take care of themselves
What are some ways to treat daytime stress incontinence seen in patients with neobladders?
Timed voiding
urethral bulking agents
urethral sling
artificial urinary sphincter
What are ways to treat nighttime stress incontinence seen in patients with neobladders?
timed voids
CIC
*if late onset, secondary to mucous plugging causing retention
What is the Bricker anastomosis?
End (ureter) to side (bowel); two separate anastomoses
*Bricker = Both ureters have anastomosis to bowel
What is the Wallace anastomosis?
Ureters Y-anastomosis together then end (ureter) to end (bowel)
WAllace = ONE ureteral anastomosis to bowel
What is the Avascular plane of Treves?
avascular region between the ileocolic artery and SMA terminal branches
defines the distal end of ileum used for conduits and orthotopic neobladders, and allows for good mobilization
What is an immediate urine leak within the abdomen/pelvis likely due to?
Treatment?
Secondary to non-water tight neoureterostomy.
Maintain stents and JP drain
What is a late urine leak within the abdomen/pelvis likely due to?
Treatment?
Secondary to ischemia or necrosis
Percutaneous drain and stomal catheter; if unresolved, then reoperation in future
Is a history of prior pelvic radiation a contraindication to getting a neobladder?
No. Classically, transverse colon would only be used, but now can make intra-operative decision to utilize distal ileum
Does a non-refluxing ureterointestinal anastomosis prevent increased upper tract pressure?
What about decreasing upper tract bacterial colonization?
It does decrease upper tract pressure
It does NOT decrease bacterial colonization of upper tract
Most common etiology of a dusky stoma post-operatively?
How should you work it up?
- Normal immediately after surgery
- Surgical technique (tension causing thrombosis, mesentery hematoma, inadequate blood supply)
If persistently dusky, consider loop endoscopy to define level of ischemia
