Bowel and Rectal Trauma

Mechanisms

1. Gunshot wounds --> GI injury in 80%
2. Stab wounds --> in 20%
3. Blunt abdo --> ~5%
- shearing from mesentery secondary to deceleration
- or bursting of a closed loop of bowel, often as part of a seat belt pattern of injury
- lumbar spine f# = high association with colon bowel injury.


Diagnosis

Penetrating trauma
- as per protocol:
- laparotomy for all gunshots
- laparoscopy +/- laparotomy for stabs anteriorly
- CT for flank / posterior wounds

Blunt trauma
- abdominal tenderness is the most common finding with perforated bowel injuries
- presence of peritoneal signs rare initially but mandates exploration.

CT features
- pneumoperitoneum
- bowel wall thickening
- mesenteric fat streaking, mesenteric haematoma, blush (assoc. with bucket-handle injury of mesentery vs bowel)
- intraperitoneal collections >3cm + multiple sites; without solid organ injury --> high risk of bowel injury.


Management

1. Operative principles
- define all injuries
- decide on repair: simple, resection, defunction, damage control
- debride when devitalized
- establish clean bowel edges in area of repair

2. Staple vs sew?
- no evidence but
- sew or care with staplers when bowel is very oedematous

3. Damage control
- should leave bowel in discontinuity

4. Duodenal injury
- suspect with retroperitoneal haemoatoma, or crepitus or bile staining along edge of duodenum.
- explore via Kocher maneuver, reflect mesentery of right colon.
- most can be managed by raepair or resection and anastomosis.
- severe if destructive e.g. missile, part 1-2, >24h post interval, CBD damaged
--> may need a piece of ejunum as a Roux-en-Y over the defect if cannot be repaired (35-40cm; retrocolic)
--> side-side repair prefered if defect is large.
May consider pyloric exclusion via gastrotomy, close pylorus with absorbable suture (most reopen in 2-3w), gastrojejunostomy

5. Small bowel injury
- usually closed primarily
- if multiple holes in proximity, may be resected and anastomosed.

6. Colon injury

Anatomy
Takes up space; commonly injured in penetrating wounds
- 20% of stabs, 80% of gunshots
Fixed to retroperitoneum so can be subtle manifestations without intraperitoneal signgs

Mechanisms
Less commonly injured in blunt trauma (<5%), but can be, by:
- Deceleration --> mesenteric avulsions, causing ischaemia
- Perforation --> seatbelt compression of large bowel loops can cause rupture
- Haematoma / contusion --> can result in delayed perforations.
Beware seatbelt pattern

Bugs
No other organ injury associated with more septic complications

Examination
Entrance, exit wounds
Contusions, seatbelt signs
Abdominal tenderness (most common feature)
PR bleeding
Pneumoperitoneum
Later, distention, ileus, sepsis, peritonism.

Investigations
Remember FAST and DPL may be inadequately sensitive due to inability to evaluate retroperitoneum.
- helpful if +ve
- DPL: 100,000 RBCs, 500 WBCs, bile / faecal / vegetable matter.
CT helpful in retroperitoneal stab wound injuries
Serial exam is very useful in selected cases.

CT features
trajectory of penetration
mesenteric fat stranding, haematoma
bowel wall thickening
fluid collections, free air
extravasation of contrast
--> stratefied into risk: low (discharge), medium (serial obs) or high (laparotomy)

Grading
AAST colon injury scale exists
- grades by I contusion / partial thickness II,III  laceration or IV,V transection
But much easier to think in terms of destructive (need to debride / resect) or non-destructive.

Management
Carefully inspect all bowel for holes
Debride
Primary repair preferred if at all possible
- reduced overall complications, less sepsis, better wound outcomes
If unable, then try to resect and anastomose
Colostomy in extreme cases where delay to presentation >12h, overt peritonitis, patient factors make unsafe to join
Damage control in necessary situations
- no joins or stomas
What to do with para-colic haematomas?
- if penetrating: explore
- if blunt: leave unless suspect

Complications
Sepsis rate 20%, higher if contamination, >4u transfusion, delay to present, destructive.
No diff b/n L and R colon
Shock is not a risk factor for sepsis, but placing an ostomy is.
Leak rate is low 2-5%, lower with simple repair; risk factors poorly defined but shock is not one of them.

7. Rectal injury

Suspect if:
- penetrating wound to lower abdo
- pelvic #
- perineal injury
- PR bleeding
--> do an EUA and proctoscopy.

Associated with a high rate of septic complications
- abscesses, pelvic collections, recto-cutaneous fistulae, rectovesical fistulae, wound infections, injury tract infections

7a. Intraperitoneal Rectum
- management varies greatly by anatomical site
manage these as per colon; primary repair or resect and repair if at all possible.
- if very destructive and pt factors mandate it, then hartmann's

7b. Extraperitoneal Rectum
Define, drain, divert
- define by EUA
- presacral drainage (now in select cases, no longer routine as evidence does not support).
--> transverse incision behind anus, dissect bilaterally into presacral space, place big penrose drains; avoid midline where coccygeal attachments lie
- divert with loop colostomy; if well made will not allow passage across the loop.
Suture repair?
- no evidence this helps, avoid it.  also is tricky and may make things worse
Rectal washout?
- no longer supported, no evidence of benefit and is messy.

7c Anorectal injury
Specialist territory.
Achieve haemostasis, debride, and get off to a specialist for a sphincter repair.


Jeromes Notes

Small bowel

Penetrating trauma

· SB most frequently injured intra-abdominal organ

Blunt trauma

· Greater degree of force and high rate of associated intra-abdominal injuries

· Association of transverse # of lumbar vertebrae and blunt intestinal injury

· Presence of Chance # and lapbelt contusion warrants laparotomy.

· CT and FAST are not reliable in blunt intestinal injury and so DPL should be used.

Damage control and assessment

· Bleeding mesentery: Running closure with suture or ligation

· Small bowel injury: application of Allis/babcock or suture ligation or stapling until entire extent of injury assessed.

· Run the entire length of SB. Check both sides. Where there is a suspect area of injury near the mesentery then clear mesentery. Compress bowel to find occult leak.

Definitive procedure

· >50% of circumference is missing then resect. Avoid stapled anastomosis if the bowel is oedematous

· Mesenteric laceration: control bleeding with suture ligation. If section is devascularized then resect

 

Colonic trauma

How is colonic trauma graded

• grade 1 – contusion or haematoma without devascularization, partial thickness

laceration, no perforation

• grade 2 – laceration <50% circumference

Most Grade 1 and 2 injuries can be treated by colorrhaphy.

• grade 3 – laceration >50% without transection

• grade 4 – transection of the colon

• grade 5 – transection of the colon with segmental tissue loss, devascularized

segment

For Grade 3,4 and 5 injuries the choice is between colostomy and primary resection with anastomosis – particularly for right-sided lesions. The choice depends on general condition of patient and intra-peritoneal environment.

What is the management of colonic injury

• exteriorisation not mandated

• consider

• delay

• shock

• peritoneal soiling

• degree of injury (destructive colonic injuries)

• primary repair for most cases

• exteriorisation for high risk cases

How is rectal injury diagnosed?

• High index of suspicion when there is any pentrating trauma to perineum or buttock.

• Blood on DRE is indicative.

• Proctoscopy with visualisation of blood or injury itself.

What is the management of rectal injuries

• Depends on anatomic location of injury, associated injuries and condition of patient

• Intra-peritoneal: the anterior and lateral surfaces of the upper 2/3 of rectum.

– Managed as colonic injuries

primary repair, resection alone (Hartmann’s) or resection and anastomosis (+/- proximal diversion) depending on complexity of wound, contamination, patient condition and suspicion of injuries to EP rectum.

• Extra-peritoneal: The lower 1/3 and posterior surface of the upper 2/3.

• Proximal EP: upper 2/3 – managed in similar manner to IP rectal injuries following mobilization of proximal EP rectum.

• Distal EP: Lower 1/3

– If wound is accessible easily then primary repair and diversion

-       If the wound is inaccessible then proximal diversion and pre-sacral drainage (curved incision between anus and tip of cocyx to insert a penrose drain in front of Waldeyer’s fascia)

-       Proximal diversion is usually via sigmoid colostomy

-       The efficacy if distal rectal washout questioned. Probably has a place in severe military-type wounds.

 

What are the common complications after colon and rectum surgery?

• Mortality: 5% - 20% emergency and 2% elective

• Immediate; Early (30 days); Late (>30 days).

• Immediate: Bleeding

• Early: General: Cardiac (arrythmia, MI, CCF) or pulmonary (Atelactasis, pneumonia, aspiration, PE), infectious (urinary tract, lungs).

• Early: Specific abdominal: Ileus, fascia dehiscence and anastomotic failure

• Late: Hernia formation (30%), Stoma complications, anastomatic stricture.

What is the risk of anastomotic failure?

• Clinical leaks occur in 1-2% of colonic resections

• Subclinical and asymptomatic leaks are more common.

How do anastomatic leaks present?

• Insidious: Fever, ileus, tachycardia, faeces draining through wound or drain

• Localized or generalized peritonitis

• Septic shock

• Ileocolic and colo-colic anastomosis: May present as generalized peritonitis, colo-cutaneous fistula or localized abscess.

• Pelvic colo-rectal anastomosis: May present as a localized pelvic abscess with or without systemic toxaemia or spreading pelvic cellulitis.

How is it diagnosed?

• Clinically: Gentle rectal exam and/or proctoscopy showing anastomotic gap

• Water-soluable contrast enema

• CT with oral, IV and/or rectal contrast.

What is the treatment for anastomtic failure?

• Depends…

• An asymptomatic leak discovered incidentally does not require treatment.

• For symptomatic leaks the treatment depends on the symptoms and the presumed extent of leak.

• Generalized peritonitis: Re-laparotomy take down the anastomosis and exteroirize the ends of the anastomosis. Repeat anastomosis may be attempted with or without proximal diversion however the risks of repeat failure are greater than the primary anastomosis and would not be the standard or recommended treatment.

• Faecal fistula in absence of generalized peritonitis or uncontrolled sepsis: Intravenous hyperalimentation, ensure no distal obstruction, treatment of sepsis and take care of skin – may close spontaneously.

• Pelvic abscess: depends on degree of toxaemia and presence of proximal diversion and size of defect in anastomosis.

• Severe toxaemia in uncovered anastomosis:  re-laparotomy, washout and placement of drain with proximal diversion (small or inapparent defect) or resection and exteriorization (Hartmann’s) if large defect especially with faecal contamination.

• Mild systemic symptoms and covered anastomosis with loculated abscess: CT-guided drainage.

• Early suspected but not confirmed pelvic leak: NBM, TPN, Abx.

 

Factors Influence whether colonic injury should have colostomy:

Pt:

Age

General physiology: shock or blood loss

Extra-abdominal injury

Time since injury

Mechanism of Injury:

GSW or Blast Injury:

Colostomy is indicated as the extend of injury not present until few days later

                        Stab: Oversew

Wound

Size of Wound

Local Damage of Vascularity

Contaimination:

Faecal

R or L colon

Mass Causalities

Surgeon Experience