Timing of Cannula Reattempt After Hematoma Formation
Cannulation should be avoided at the site of hematoma until the swelling has completely resolved and anatomical landmarks are clearly visible again, which typically requires waiting until the hematoma has fully subsided. 1
Key Principle: Wait for Complete Resolution
The affected site must be rested until all swelling, induration, and edema have resolved before any reattempt at cannulation. 1 While no specific timeframe is defined in controlled studies, the guideline emphasizes that landmarks must be clearly visible before proceeding. 1
Clinical Assessment Before Reattempt
Before attempting recannulation, verify that:
- The cannulation site has healed completely 1
- The vessel has been assessed and confirmed to be normal and appropriate for cannulation 1
- Anatomical landmarks can be seen clearly through inspection and palpation 1
- All induration and edema have resolved 1
Timeframe Considerations by Access Type
For Arteriovenous Fistulae (Dialysis Access)
- Infiltrated new fistulae should be rested completely until swelling resolves, which may require establishing alternative temporary access (such as a catheter) during the healing period 1
- Large hematomas may require deferral of vascular access attempts for up to 3 months until complete resolution 2
For Arteriovenous Grafts
- Arm elevation should be maintained until swelling subsides, which may take 3 to 6 weeks 1
- Any increase in symptoms requires urgent evaluation 1
Critical Pitfalls to Avoid
Repetitive attempts to cannulate through or near an existing hematoma carry high risk of inaccurate placement, which will further exacerbate swelling and may lead to permanent vessel loss. 1 This is particularly critical for newly created arteriovenous fistulae where premature cannulation significantly increases infiltration rates. 1
Do not attempt cannulation simply because a specific timeframe has passed—the decision must be based on clinical resolution of the hematoma, not arbitrary time intervals. 1
Alternative Site Selection
If urgent vascular access is needed before the hematoma resolves, establish access at a completely different site rather than attempting cannulation at or near the affected area. 1, 2 For dialysis patients, this may involve placement of a temporary or cuffed catheter. 1
Special Circumstances Requiring Investigation
A hematoma requiring transfusion or resulting in very large size suggests underlying venous outflow stenosis and mandates referral for diagnostic angiography before any reattempt. 2 Similarly, persistent edema beyond 2 weeks in graft sites may indicate occult central venous stenosis requiring venography or other imaging. 1
Operator Skill Requirements
Only staff with demonstrated technical mastery should attempt cannulation of vessels with prior hematoma formation. 1 A protocol for minimizing vessel damage should be followed, and heparin management should be reviewed on a case-by-case basis to minimize post-procedure bleeding risk. 1