The Use of Intraoperative Fluorescent Angiography to Assess and Optimize Free Tissue Transfer in Traumatic Head and Neck reconstruction

Tuesday, September 11, 2012: 1:10 PM
J. Marshall Green DDS Bethesda, MD, USA
Robert Howard MD Bethesda, MD, USA
Patrick Basile MD Bethesda, MD, USA
Ian Valerio MD, MS, MBA Bethesda, MD, USA
Introduction: Large composite tissue defects in the head and neck region secondary to trauma have long presented complex challenges to reconstructive surgeons. Refinements in microvascular free flaps have provided composite tissues for such traumatic defects, while also aiding in facial form and function for head and neck reconstructive surgery. Employment of such complex flap transfers as well as their multiple geometries for optimization of structural reconstruction creates its own set of difficulties. For those flaps utilizing large soft tissue envelopes, limitations in angiosome size or recruitment can contribute to the potential for partial and total flap loss, thus compromising the surgeon’s reconstruction, and ultimately, negatively affecting the patient’s overall outcome.
Methods: All free tissue transfers during the last 18 months performed at a single center, Walter Reed National Military Medical Center Bethesda , were reviewed. Fluorescent indo-cyanine green angiography (Novadaq SPY® imaging) was employed in all traumatic head and neck free tissue flap reconstructions to assess flap viability and perfusion. Tissue flap perfusion was assessed after near complete harvest of the donor flap and prior to pedicle division, re-assessment was also performed after reanastomosis of donor flap vessels to recipient vessels. Areas of poor flap perfusion were excised prior to inset as confirmed via SPY® imagery assessment. Flap perfusion images pre-division of the main pedicle and post-anastomosis were correlated as well as compared with final postoperative results. Cases were then reviewed by type of flap, flap success and failure rate, and complications.
Results: A total of 56 free tissue transfers were performed over this time period, with 55 free flaps successfully performed (98.2% success rate). Further subgroup analysis of all free tissue transfers revealed 8 free tissue transfers to the head and neck region for traumatic reconstructions. These 8 head and neck free flaps included 1 latissimus, 1 vastus lateralis, 2 fibular, 4 ALT. Overall success rate was 87.5% for the head and neck flaps, 1 flap was lost, and no flaps suffered partial flap necrosis (0%). The failed flap, a free ALT flap, was lost 48hours after transfer despite promising perfusion imaging after flap elevation and inset. Of note, this patient underwent postoperative testing that revealed a hypercoagulable condition. There were no other complications encountered.
Conclusion: Free flap head and neck reconstructions can be technically challenging procedures given the complex orientation and composite tissue replacement of defects that often result from significant trauma. The routine use of intraoperative fluorescent angiography with indo-cyanine green can aid in soft tissue and boney flap perfusion assessment, pedicle evaluation prior to division and after reanastomosis, as well as perfusion evaluation prior to flap inset to optimize flap viability and coverage of critical defects. Furthermore, this technique can aid in avoidance of total and/or partial flap loss due to technical mistakes by identifying poor flap perfusion, especially when compared to pre-pedicle division. This tool can give the reconstructive surgeon invaluable information in making the decision to perform surgical delay, thereby preventing perfusion related complications. Utilizing SPY® angiography at our institution has aided us in decreasing intraoperative time, maximizing flap size, better inset of flaps, reduction in take-backs for debridement, delayed wound healing issues, while minimizing overall morbidity for complex wounds of the head and neck .
References
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