Intestinal obstruction and hernia Flashcards
how do you classify bowel obstructions
mechanical vs non obstruction motility disorder
partial versus complete
low vs high grade
what are the most common causes of small bowel obstruction (SBO)
- post operative adhesions (nearly 75% of SBOs)
- -5-30% patients develop SBO after abdo surgery - hernia
- malignancy
- -mets (i.e ovarian) rather than primary is most common
other-- IBD abscess intusussception meckel's diverticulum bezoar gallstone illeus volvulus radiation enteritis traumatic intramural hematoma congenital abnormalities SMA syndrome
what % of patients with SBO needs surgical intervention during index admission
up to 25% (though more likely 5-10%) of patients with SBO
patients without prior hx of abdominal surgery (“virgin abdo”) are far more likely to need surgery to resolve (because shouldnt be having problems like from adhesions etc)
classic SBO symptoms
colicky abdo pain (localized or diffuse)
nausea
emesis (bilious more concerning)
abdominal distension/bloating
obstipation (**but it is possible to have BMs if obstruction is more proximal)
?similar previous episodes of SBO
what might you find on exam of SBO patient
fever, tachy
distended abdo
tenderness to percussion or palpation
tympanic abdo
focal vs diffuse peritonitis
look for erythematous, tender bulges (groin, midline, umbilicus, previous surgical incision sites, parastomal)
what affects clinical presentation of SBO
anatomical site of obstruction
severity
time duration since onset of obstruction
how do you grade severity of SBO
complete
partial
open loop
closed loop
complete SBO
no distal passage of stool or gas
partial SBO
narrowing of passage with some matter going thru
closed loop SBO
more worrying
both proximal and distal segment of bowel loop are obstructed
open loop SBO
proximal decompression is achieved by nasogastric decompression
how sick is the patient? (what signs to look for…)
alert?
comfortable?
lethargic?
vitals/hemodynamic status?
emesis? (i.e 1L of bilious, multiple episodes?)
pain? opioid requirement?
blood work–WBC, BUN, Cr, lytes, lactate
imaging–>plain films vs CT abdo pelvis
what do you look for on plain film for SBO
more than 3 air fluid levels
caliber of small bowel more than 3 cm
step ladder pattern
*diagnostic only in 50-60% of cases and have high sensitivity only for high grade obstruction
what role does CT scan play in initial eval of SBO
go to imaging that completes initial eval
fast and relatively accessible, shows presence of obstruction
shows small vs large bowel
can show whether partial/complete/high/low grade
shows anatomical position and transition point and associated abnormalities
what role does CT scan play in initial eval of SBO
go to imaging that completes initial eval
fast and relatively accessible, shows presence of obstruction
shows small vs large bowel
can show whether partial/complete/high/low grade
shows anatomical position and transition point and associated abnormalities
*dont forget to check GFR before
intrinsic causes of SBO
IBD
neoplasias
vascular lesions
hematoma
intussusception
intraluminal causes of SBO
gallstones
bezoars
foreign bodies
extrinsic causes of SBO
adhesions
hernias
endometriosis
hematomas
what are the CT criteria for SBO
dilated small bowel loops (greater than 2.5 cm from outer wall to outer wall) proximally to normal caliber or collapsed loops distally
high grade–> 50% difference in caliber between proximal dilated bowel and distal collapsed bowel
how are most SBO manage
non operative
i.e for partial SBO early post op period crohns hemodynamically stable no clinical deterioration improvement within 12-24 hours motility related causes ie ileus
manage with... serial abdo exam bowel rest aggressive IVF rescus electrolyte correction NG tube decompression serial abdo xray abx? TPB?
how does NG decompression work for SBO
allows edema in wall of bowel or adhesions to settle and allows affected area to heal
works in majority of people with partial obstruction
what are the endpoints of conservative SBO management
resolution of pain
distention
nausea/emesis
passage of flatus and stool
normalization of vital signs and bloodwork
what patients need operations for SBO
hemodynamic instability
fever, tachy, worsening leukocytosis
peritonitis
strangulation
evidence/suspicion bowel perf
no improvement with supportive care
virgin abdo
closed loop
non adhesive SBO
“dont let the sun rise and set on an SBO”…i.e do something if not improving
classification of LBO
partial or complete
extrinsic or intrinsic
mechanical or adynamic
competent ileocecal valve–> makes it a closed loop obstruction
*large bowel is less mobile than small bowel
causes of LBO
*more commonly require surgical intervention than SBO
neoplasm volvulus inflammatory (IBD, radiation, diverticulitis) hernia intussusception adynamic (ogilvie's) stricture foreign body fecal impaction
what is the significant of the ileocecal valve in an LBO
essentially makes an LBO a closed loop obstruction
competent valve causes pressure to build up
cecum is thus at highest risk for necrosis/perforation
what is normal colon diameter
less than 6 cm
more than 9cm is dilated
what is ogilvie’s syndrome
adynamic bowel
only LARGE BOWEL
exact pathophys is poorly understood
end result is disruption of colon motility, leading to distention
can lead to ischemia and perf if untreated
commonly seen in trauma, severe infection and cardiac disease
what is paralytic ileus
adynamic bowel
*dilatation of ENTIRE GI TRACT
people become massively distended
commonyl seen post abdo/ortho/obgyn procedures
onset around POD4
predisposing factors–> manipulation of bowels, meds (opioids, anticholinergics), immobilization, electrolyte abnormalities etc.
classic symptoms of paralytic ileus
abdo distension, pain, nausea, vomiting
with or without obstipation
with or without resp distress (from distenstion)
tx for paralytic ileus
aggressive supportive care
bowel rest NG/rectal tube or lower scope decompression IV fluids correct lytes minimize opioids, anticholinergics mobilize treat underlying illness gentle bowel protocol neostigmine or methylnaltrexone
groin mass ddx
hernia lymphadenopathy hydrocele/spermatocele hematoma/femoral artery aneurysm undescended testes/testicular torsion psoas abscess neoplasm
how do you classify hernias
anatomical location
epigastric umbilical incisional inguinal femoral spigelian lumbar richter's
define spigelian hernia
lateral aspect of rectus along the semicircular line of douglas–transition of two layers to one layer of rectus
high risk for complication
hard to detect
define richters hernia
10% of strangulated hernias
not a full thickness of bowel hernia –no actual obstruction but ongoing ischemia in the wall
ileum most common place –herniation of antimesenteric wall without compromise of entire lumen
progress more quickly to gangrene
maydl’s hernia
REDUCTION CONTRAINDICATED
“w” through the internal inguinal ring
littre’s hernia
herniation of meckel’s diverticulum
amyand’s hernia
vermiform appendix herniation
hesselbach’s triangle boundaries
lateral–> inferior epigastric BVs
medial–> rectus abdominis
inferior–> inguinal ligament
pantaloon hernia
both direct and indirect hernia at the same time
why do we care about hesselbach’s triangle
it is where the direct hernias occur –> direct hernia’s protrude through the floor of hesselbach’s triangle due to weakness of transversalis fascia
result of increased abdo pressure (cough, COPD, constipation, obesity)
why do we care about hesselbach’s triangle
it is where the direct hernias occur –> direct hernia’s protrude through the floor of hesselbach’s triangle due to weakness of transversalis fascia
result of increased abdo pressure (cough, COPD, constipation, obesity)
indirect hernia
lateral to epigastric vessels
secondary to patent processus vaginalis, pass through internal inguinal ring
direct hernia
medial to epigastric vessels
direct hernia’s protrude through the floor of hesselbach’s triangle due to weakness of transversalis fascia
what is the most common type of hernia
indirect in males
what is the most common general surgical procedure in north america
inguinal hernia
define femoral hernia
below inguinal ligament and medial to femoral vein
more common on right than left
elderly women more common
need to repair due to high risk of strangulation
risk factors for inguinal hernia
males
family history
genetic–immature type III:type I collagen
aneurysmal disease, collagen disease, hiatal hernia, sleep apnea, smoking
increased intra abdo pressure
older age
reducible hernia
spontaneous or manual return of hernia sac content into abdo cavity
incarcerated hernia
inability to reduce the contents
strangulated hernia
incarcerated with signs of bowel compromise
how should you examine a patient for a hernia
standing position
can be difficult to distinguish direct or indirect on exam
do you need imaging to dx hernia
no, not if clinical presentation clearly consistent with reducible inguinal hernia
obese/patients without history might need imaging
any dx uncertainty–image
who gets surgery for a hernia
all females with grain hernia
femoral hernia
symptomatic hernia
incarcerated or strangulated hernia (emergent)
when should you NOT try manual hernia reduction
if there are any signs of bowel compromise–do not want gangrenous piece of bowel in peritoneal cavity
how to reduce a hernia
place patient in trendelenburg position and apply constant pressure to the bulge until returns to peritoneal cavity
no surgical management of inguinal hernia
watchful waiting acceptable for men with minimal symptoms or asymptomatic inguinal hernia (incarceration is 0.3-3% per year)
weight reduction
smoking cessation
educate about sx of incarceration and strangulation
sliding hernia
part of the wall is composed of part of another organ (i.e bowel plus bladder)
what is the ddx of groin pain and/or mass
inguinal hernia
femoral hernia
muscle strain
adenopathy
how do inguinal hernia patients often present (on history)
intermittent groin discomfort or “heaviness” that is more prominent with activity and after standing for long periods of time
what test should be ordered to confirm a femoral hernia
CT pelvis
how do you approach treatment of an acutely incarcerated femoral hernia
expeditious exploration and repair of the hernia
use an open incision above the inguinal ligament that allows the surgeon to go through the inguinal floor to identify the femora canal and address the contents of the hernia
once reduced, use a McVay type repair (Cooper’s ligament repair) with placement of prosthetic mesh
define indirect inguinal hernia
inguinal hernia in which abdominal contents protrude through the internal inguinal ring through a patent PROCESSUS VAGINALIS into the inguinal canal
in men, hernia sacs follow the spermatic cord and may descend into the scrotum
in women–may present as labial swelling
define direct inguinal hernia
inguinal hernia that protrudes through the HESSELBACH TRIANGLE and MEDIAL to the ipsilateral inferior epigastric vessels
develop initially as tears to the abdominal well within hesselbach’s triangle (transversus abdominis musculature)
define femoral hernia
hernia that protrudes through the femoral canal, which is bound by the INGUINAL LIGAMENT superiorly, FEMORAL VEIN laterally and PYRIFORMIS and PUBIC RAMUS medially
femoral hernia is BELOW inguinal ligament
define umbilical hernia
hernia that results from improper closure of the abdominal wall defect where the umbilical cord was in utero
80% will close spontaneously by 2 years of life
can also be acquired–subclinical defects increase in size due to increased intra-bdbominal pressures (pregnancy, ascites, excess weight gain)
define a Little hernia
any hernia that contains a meckel’s diverticulum
define Amyand’s hernia
inguinal hernia that contains the appendix
define de garengoet’s hernia
femoral hernia that contains the appendix
define richter’s hernia
herniation of part of the bowel wall through any hernia defect
unique in that it may or may not be associated with intestinal obstruction–often smaller and more difficult to diagnose
area of incarcerated intestine can develop ischemia and necrosis when not dx
define spigelian hernia
hernia just lateral to the rectus sheath and located at the semi-lunar line or the lower limits of the rectus sheath
define obturator hernia
herniation along the obturator canal alongside the obturator vessels and obturator nerve
most common in women (esp multiparous women) with history of recent weight loss
mass palpable in medial thigh
howship-romberg sign associated with 50% of patients with obturator hernias–> pain along inner thigh induced by hip flexion, abduction, internal rotation or external rotation
define sliding hernia
indirect inguinal hernia with hernia sac containing either sigmoid colon or cecum
sac will contain the attachment of the intestines
what is incarceration
trapping of the abdominal contents within the hernia sac (does not spontaneously reduce)
what is strangulation
blood supply to the trapped intra-abdominal contents becomes compromised leading to ischemia, necrosis, and ultimately perforation
what are the boundaries of hesselbach’s triangle
edge of RECTUS MUSCLE medially, the INGUINAL LIGAMENT inferiolaterally, and INFERIOR EPIGASTRIC VESSELS superiolaterally–> this is where direct hernias are found
(indirect hernias as lateral to this)
what is cooper’s ligament
aka pectineal ligament
fibrous structure that extends from the pubic tubercle mediallyand extends posteriotly to the femoral vessels
define the boundaries of the femoral canal
between the inguinal ligament, cooper’s ligament, femoral vein
what is the rate of inguinal hernia incarceration over 2 years for those with asymptomatic hernias
0.18% (and no strangulations)
about 1/3 patients with FEMORAL hernias developed acute events requiring emergency surgery so dont wait for them
which is better in hernia repair–suturing native tissue closed or using mesh prosthetic and plug?
mesh prosthetic plus plug has lower recurrence rates
what presentation of a hernia is most concerning for strangulation
hard and tender hernia when palpated
