Mateusz Gładysz FESSH prep

FESSH prep Microsurgery Type and timing of pedicle thrombosis, salvage rates, implantable Doppler monitoring, thrombolysis at re exploration, single versus double venous anastomosis

Free-flap monitoring and salvage

Last reviewed v1.0

FESSH-044Microsurgery●●● advanced

Regarding postoperative monitoring and salvage of free flaps:

  1. 1.After free tissue transfer, venous thrombosis is more common than arterial thrombosis and carries a higher salvage rate on re-exploration.

  2. 2.Arterial thromboses characteristically present later than venous thromboses, so arterial monitoring becomes more important from the second postoperative day onwards.

  3. 3.Adjunctive thrombolysis with tissue plasminogen activator or urokinase at re-exploration has been shown in comparative series to significantly increase the flap salvage rate compared with anastomotic revision and thrombectomy alone.

  4. 4.In pooled comparative data, implantable Doppler monitoring is associated with a lower flap failure rate and a higher salvage rate than clinical assessment alone, at the cost of a small false-positive rate.

  5. 5.Meta-analysis supports performing two venous anastomoses where feasible, with lower rates of venous thrombosis, surgical revision and flap failure than a single venous anastomosis.

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Question ID
FESSH-044
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. After free tissue transfer, venous thrombosis is more common than arterial thrombosis and carries a higher salvage rate on re-exploration.

    True

    In Bui's series of 1,193 free flaps, 6% were re-explored, most often for pedicle thrombosis (53%) or haematoma (30%); venous thrombosis was more common than arterial (74 versus 26%) and had a higher salvage rate (71 versus 40%), with overall flap survival of 98.8%. Kroll's 990-flap series likewise found venous thrombosis (54%) more frequent than arterial (20%) or combined (12%). Venous obstruction produces early, recognisable congestion, and the flap tolerates a period of venous congestion better than complete arterial ischaemia, which explains why venous events are both commoner and more recoverable.

    • Bui DT, Cordeiro PG, Hu QY, Disa JJ, Pusic A, Mehrara BJ. Free flap reexploration: indications, treatment, and outcomes in 1193 free flaps. Plast Reconstr Surg. 2007;119(7):2092-2100. PMID 17519706
    • Kroll SS, Schusterman MA, Reece GP, Miller MJ, Evans GR, Robb GL, et al.. Timing of pedicle thrombosis and flap loss after free-tissue transfer. Plast Reconstr Surg. 1996;98(7):1230-3. PMID 8942909

  2. 2. Arterial thromboses characteristically present later than venous thromboses, so arterial monitoring becomes more important from the second postoperative day onwards.

    False

    The reverse is true. Kroll found that 80% of thrombi occurred within the first two postoperative days, that almost all purely arterial thrombi (90%) occurred before the end of the first postoperative day whereas 41% of venous thrombi occurred later, and that no flap with a thrombosis after the third day was salvaged. The authors concluded that arterial monitoring is most critical immediately after surgery and that from the second postoperative day venous monitoring becomes progressively more important, with the cost-effectiveness of monitoring greatest in the first two days.

    • Kroll SS, Schusterman MA, Reece GP, Miller MJ, Evans GR, Robb GL, et al.. Timing of pedicle thrombosis and flap loss after free-tissue transfer. Plast Reconstr Surg. 1996;98(7):1230-3. PMID 8942909

  3. 3. Adjunctive thrombolysis with tissue plasminogen activator or urokinase at re-exploration has been shown in comparative series to significantly increase the flap salvage rate compared with anastomotic revision and thrombectomy alone.

    False

    The comparative series available have not shown a salvage benefit. In Chang's review of 74 compromised breast flaps, anastomotic revision alone salvaged 92.7% and revision with adjuvant thrombolysis 84.8%, a difference that was not significant, although thrombolysed flaps developed less fat necrosis. Bui found no difference in salvage between flaps needing thrombolysis or vein grafting and those revised only, and in the 2,138-flap MD Anderson breast series thrombolytics and heparinisation were associated with higher loss, probably reflecting their use in the most compromised flaps. Panchapakesan salvaged 30% of refractory flaps given thrombolytics and framed the drug as a selective rescue rather than a routine adjunct.

    • Chang EI, Mehrara BJ, Festekjian JH, Da Lio AL, Crisera CA. Vascular complications and microvascular free flap salvage: the role of thrombolytic agents. Microsurgery. 2011;31(7):505-9. PMID 21630338
    • Bui DT, Cordeiro PG, Hu QY, Disa JJ, Pusic A, Mehrara BJ. Free flap reexploration: indications, treatment, and outcomes in 1193 free flaps. Plast Reconstr Surg. 2007;119(7):2092-2100. PMID 17519706
    • Chang EI, Chang EI, Soto-Miranda MA, Zhang H, Nosrati N, Crosby MA, et al.. Comprehensive Evaluation of Risk Factors and Management of Impending Flap Loss in 2138 Breast Free Flaps. Ann Plast Surg. 2016;77(1):67-71. PMID 25003429
    • Panchapakesan V, Addison P, Beausang E, Lipa JE, Gilbert RW, Neligan PC. Role of thrombolysis in free-flap salvage. J Reconstr Microsurg. 2003;19(8):523-30. PMID 14722839

  4. 4. In pooled comparative data, implantable Doppler monitoring is associated with a lower flap failure rate and a higher salvage rate than clinical assessment alone, at the cost of a small false-positive rate.

    True

    Chang's systematic review and meta-analysis of six comparative studies found that an implantable Doppler probe significantly lowered the flap failure rate (risk ratio 0.40) and raised the successful salvage rate (risk ratio 1.73), with pooled sensitivity of 1.00 against 0.98 for clinical assessment and a false-positive rate of 0.01 against zero, while noting that clinical assessment remains the gold standard. Chae's earlier systematic review of 184 publications identified the implantable Doppler as the technique with the largest number of comparative studies demonstrating effectiveness compared with clinical monitoring, alongside near-infrared spectroscopy and laser Doppler flowmetry; it is particularly valuable for buried flaps.

    • Chang TY, Lee YC, Lin YC, Wong ST, Hsueh YY, Kuo YL, et al.. Implantable Doppler Probes for Postoperatively Monitoring Free Flaps: Efficacy. A Systematic Review and Meta-analysis. Plast Reconstr Surg Glob Open. 2016;4(11):e1099. PMID 27975015
    • Chae MP, Rozen WM, Whitaker IS, Chubb D, Grinsell D, Ashton MW, et al.. Current evidence for postoperative monitoring of microvascular free flaps: a systematic review. Ann Plast Surg. 2015;74(5):621-32. PMID 23038130

  5. 5. Meta-analysis supports performing two venous anastomoses where feasible, with lower rates of venous thrombosis, surgical revision and flap failure than a single venous anastomosis.

    True

    Riot's meta-analysis of 27 articles and 6,842 flaps found a failure rate of 3.1% with a single venous anastomosis against 1.3% with two (odds ratio 0.511), thrombosis rates of 3.1% against 2.3% (odds ratio 0.586) and revision rates of 7.7% against 6% (odds ratio 0.601), and recommended double anastomosis whenever feasible. Chaput's head-and-neck meta-analysis of 3,684 flaps confirmed lower venous thrombosis (2.74 versus 4.54%) and revision rates (6.04 versus 11.87%) with two veins, although the failure-rate difference there (1.51 versus 5.03%) did not reach significance. Venous problems remain the most frequent cause of flap failure and revision.

    • Riot S, Herlin C, Mojallal A, Garrido I, Bertheuil N, Filleron T, et al.. A Systematic Review and Meta-Analysis of Double Venous Anastomosis in Free Flaps. Plast Reconstr Surg. 2015;136(6):1299-1311. PMID 26595023
    • Chaput B, Vergez S, Somda S, Mojallal A, Riot S, Vairel B, et al.. Comparison of Single and Double Venous Anastomoses in Head and Neck Oncologic Reconstruction Using Free Flaps: A Meta-Analysis. Plast Reconstr Surg. 2016;137(5):1583-1594. PMID 27119931