Note 01
The Absent Pulse After RSVG Repair in Complex Limb Trauma: Causes, Management, and Prevention
Following a reversed saphenous vein graft (RSVG) repair in complex extremity trauma, absence of pulse over the graft and distally should be considered a vascular emergency. The assumption must be that the reconstruction has failed or is inadequately perfusing the limb until proven otherwise.
Causes of Absent Pulse After RSVG Repair
1. Inflow Problems
* Missed proximal arterial injury
* Proximal thrombosis
* Intimal flap or dissection
* Inadequate thrombectomy
* Arterial spasm
* Clamp-related injury
* Persistent hypotension or severe shock
2. Graft-Related Problems
* Early graft thrombosis
* Graft twist
* Graft kink
* Excessive graft length causing redundancy
* Graft tension-graft is too short
* Poor-quality vein conduit
* Using of graft without reversing
* Size mismatch between graft and artery
* External compression by hematoma, edema, or fracture fragments
3. Anastomotic Problems
* Technical stenosis
* Back-wall stitch
* Purse-string effect
* Inadequate spatulation
* Anastomotic thrombosis
* Intimal flap at the anastomosis
* Change in graft geometry after fracture fixation or limb repositioning
4. Outflow Problems
* Distal thrombosis
* Distal embolization
* Missed distal arterial injury
* Severe distal vasospasm
* Poor tibial runoff
* Extensive microvascular destruction from crush injury
5. Compartment Syndrome
A technically perfect repair may fail because tissue pressure exceeds capillary perfusion pressure.
Causes include:
* Prolonged ischemia
* Reperfusion injury
* Crush trauma
* Combined arterial and venous injury
* Massive fluid resuscitation
* Tight fascial compartments
6. Venous Outflow Obstruction
* Major venous injury
* Venous thrombosis
* Venous ligation
* Severe limb edema
Failure to address venous outflow may compromise arterial inflow despite a patent graft.
What Should We Do When No Pulse Is Found?
Immediate Response
Do not leave the patient under observation.
Do not assume vasospasm.
Do not wait for spontaneous improvement.
Step 1: Verify the Finding
* Palpate proximal and distal pulses
* Assess Doppler signals
* Check graft Doppler signal
* Confirm systemic blood pressure
* Exclude external compression from dressings, splints, casts, or positioning
Step 2: Assess the Graft
If no Doppler signal is detected:
* Re-explore immediately
* Assess graft filling
* Assess pulsatility
* Evaluate inflow and outflow
Step 3: Check Inflow
Questions:
* Is the proximal artery patent?
* Is there an unrecognized proximal lesion?
* Is there residual thrombus?
Management:
* Repeat thrombectomy
* Repair intimal flap
* Extend reconstruction if necessary
Step 4: Check Anastomoses
Inspect for:
* Technical narrowing
* Twisting
* Kinking
* Back-wall sutures
* Anastomotic thrombus
Revise the anastomosis whenever there is doubt.
Step 5: Check Outflow
Evaluate:
* Distal arteries
* Distal thrombosis
* Runoff vessels
Management:
* Distal thrombectomy
* Additional bypass extension
* Distal reconstruction if required
Step 6: Rule Out Compartment Syndrome
Perform fasciotomy liberally when risk factors exist:
* Ischemia >4–6 hours
* Combined arterial and venous injury
* Massive swelling
* Crush injury
* Reperfusion after prolonged ischemia
A delayed fasciotomy is often a limb-loss event.
Step 7: Completion Imaging
Before leaving the operating room:
* Completion angiography
* On-table angiogram
* Duplex ultrasound where available
Never rely solely on visual inspection.
How Can We Prevent This Problem?
Before Reconstruction
1.Damage Control Principles
* Correct hypothermia
* Correct acidosis
* Correct coagulopathy
* Restore adequate blood pressure
2.Careful Vessel Assessment
* Debride injured artery back to healthy intima
* Identify occult intimal injury
* Evaluate proximal and distal segments thoroughly
3.Optimize Distal Runoff
* Perform thrombectomy proximally and distally
* Confirm excellent back-bleeding
* Confirm adequate forward inflow
During Reconstruction
1.Conduit Selection
Use:
* Healthy great saphenous vein whenever possible
Avoid:
* Varicose segments
* Thin-walled damaged vein
* Inadequate diameter conduit
2.Technical Excellence
Ensure:
* No twist
* No kink
* No tension
* Proper graft length
* Wide spatulated anastomoses
* Good vessel alignment
Recheck After Fracture Fixation/Adjustments
A graft that is perfect before orthopedic fixation/adjustments may kink afterward.
Always reassess:
* Pulse
* Doppler signal
* Graft lie
after final skeletal stabilization.
Before Closure
Mandatory checklist:
✓ Palpable pulse
✓ Strong Doppler signal
✓ Good graft pulsatility
✓ Warm foot
✓ Adequate capillary refill
✓ Completion angiography or duplex assessment
✓ Assessment for compartment syndrome
✓ Fasciotomy performed when indicated
After Closure
Continuous surveillance:
* Hourly pulse checks initially
* Doppler monitoring
* Limb examination
* Early return to theatre if deterioration occurs
Any loss of pulse after reconstruction should be assumed to represent graft compromise until proven otherwise.
Take-Home Message
The absent pulse after trauma vein graft repair is not a diagnosis—it is a warning sign.
The cause is almost always one of four mechanisms:
1. Inadequate inflow
2. Graft failure
3. Inadequate outflow
4. Compartment-related perfusion failure
The safest approach is aggressive reassessment, liberal use of completion imaging, meticulous technical execution, and early fasciotomy when risk factors exist.
The limb is usually lost not because the first repair failed, but because failure of the repair was recognized too late….
