Incidence of heparin-induced thrombocytopenia in lower-extremity free flap reconstruction correlates with the overall surgical population

Heparin-induced thrombocytopenia in lower extremity free tissue transfers

BACKGROUND

Heparin-induced thrombocytopenia (HIT) an immunologically mediated reaction to heparin products, can lead to severe thrombocytopenia and potentially life-threatening thrombotic events. In microsurgery, a missed or delayed diagnosis of HIT can cause complications requiring revision operations, flap loss, or limb loss. Surgeons must remain vigilant for this uncommon yet potentially devastating condition and keep abreast of management strategies.

METHODS

CPT and ICD-10 codes in electronic medical records were used to collect demographic information, clinical courses, and outcomes for patients with a HIT diagnosis who underwent lower extremity free tissue transfer in one institution.

RESULTS

The authors' institution performed 415 lower extremity free flaps in 411 patients during the 10-year study period. Flap salvage rate was 71% for compromised lower extremity flaps without HIT, and 25% in those with HIT. Four patients (four flaps) met study inclusion criteria during the study period. Three of the four flaps failed and were later debrided; one was rescued after a takeback for anastomosis revision. Two patients successfully underwent a delayed second free flap procedure after recovery, and one was salvaged with a pedicled muscle flap.

CONCLUSIONS

Surgeons should monitor for HIT by establishing coagulation panel and platelet count baselines and trending these values in the early post-operative period for patients treated with heparin products. The 4T score can be used to screen for HIT with high clinical suspicion. Arterial thrombosis or poor flap perfusion despite sound microvascular technique could suggest HIT. Surgical and medical management including strict heparin avoidance can prevent adverse events for these patients.

Distal facial vein catheterization for prevention and management of thrombosis in vascularized lymph node transfers

BACKGROUND

This study investigated the outcomes of the distal facial vein catheterization (DFVC) to manage venous thrombosis in vascularized submental lymph nodes (VSLN) flap transplantations.

METHODS

Between March 2017 and December 2020, patients who underwent VSLN flaps were divided into Group I: combined delayed primary retention sutures (DPRS) with DFVC, and Group II: DPRS alone. Primary outcomes were early (within 72 h) and late venous thrombosis. Secondary outcomes included other nonvascular complications and mechanical factors of the thrombosis.

RESULTS

A total of 105 patients who underwent 106 VSLN flaps, including 37 and 69 flaps in Groups I and II, respectively, were included. There were no statistically significant differences in age, body mass index, Taiwan lymphoscintigraphy staging, and surgical factors between the two groups (all p > 0.05). Early venous thrombosis requiring re-exploration developed in one (2.7%) and three (4.3%) flaps in Groups I and II, respectively (p = 0.20). One flap (2.7%) and eight (11.5%) flaps developed late venous thrombosis in Groups I and II, respectively (p < 0.01). There was no statistically significant difference in total complication rates between both groups (p = 0.9).

CONCLUSION

VSLN flap transplantation had a significantly higher risk of late venous thrombosis. DFVC significantly decreased the late venous thrombosis.

Parallel Cross-Leg Free Flap with Posterior Tibial Artery Perforator Pedicle Propeller Cable Bridge Flap for the Treatment of Lower Extremity Wounds: A Case Series Report

BACKGROUND

A cross-leg flap can be used to treat severely injured lower limbs but associated with complications. Herein, we describe a technique of a parallel cross-leg free flap combined with posterior tibial artery perforator pedicle propeller cable bridge flap for the treatment of lower extremity wounds.

METHODS

The artery and veins of the free flap are anastomosed to the contralateral posterior tibial artery and vein, respectively. The vascular pedicle is wrapped with a posterior tibial artery perforator pedicle propeller flap. The legs are allowed to remain in a straight, relaxed position which is maintained with a bandage or Kirschner wire placed at the distal limbs. Pedicle division is performed around 21 days after flap creation, and the posterior artery is re-anastomosed and pedicled flap returned to its original position.

RESULTS

From June 2017 to March 2020, 7 patients with lower extremity wounds and tissue loss received reconstruction with this method. The recipient vessels for all flaps were the posterior tibial artery and vein. The average operation time was 5 hours. The average time to ambulation was 4 weeks, and the average follow-up time was 13.7 months. All flaps survived, and limb salvage was successful in all patients. Patients were not uncomfortable with the limbs held in position until pedicle division, and there were no complications. At the final follow-up, the function of all limbs was normal, and the esthetic appearance was acceptable to all patients.

CONCLUSIONS

The method described overcomes the disadvantages of traditional cross-leg flaps for the treatment.

Heparin-induced thrombocytopenia and thrombosis in primary lymphedema patients who underwent vascularized lymph node transplantations

BACKGROUND

Heparin-induced thrombocytopenia and thrombosis (HITT) may result in microsurgical flap failure. This study investigated the outcomes of HITT in primary lymphedema patients who underwent vascularized lymph node transplantations (VLNT).

METHODS

Between 2012 and 2019, primary lymphedema patients who underwent VLNTs were retrospectively included. The 4Ts score was used to categorize patients into HITT (scores of 5-7) and non-HITT (score < 5) groups. Outcome evaluations included the re-exploration rate, success rate, circumferential differences, cellulitis episodes, and Lymphedema Specific Quality of Life Questionnaire (LYMQoL) scores.

RESULTS

Twenty-six and 15 patients with 31 and 16 VLNTs were included in the HITT and non-HITT groups, respectively. The HITT group had significantly greater first, second and third re-exploration rates of 38.7% (12/31), 25.7% (8/31), and 6.5% (2/31) than the non-HITT group (6.3%, 0%, and 0%, all p < 0.01), respectively. The platelet counts significantly decreased by 21.0% in the HITT group compared with the non-HITT group (14%) on postoperative Day one (p < 0.01) with a cutoff value of 17% and AUC = 0.88.

CONCLUSIONS

HITT may cause a high re-exploration rate of VLNTs in primary lymphedema patients. The 17% reduction in platelets on postoperative day one was an early sign for detecting HITT.