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J Reconstr Microsurg 2020; 36(03): 182-190
DOI: 10.1055/s-0039-1700539
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A Novel Technology for Free Flap Monitoring: Pilot Study of a Wireless, Biodegradable Sensor

Hiroki Oda
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Levent Beker
3   Department of Chemical Engineering, Stanford University, Stanford, California
,
Yukitoshi Kaizawa
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Austin Franklin
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Jung Gi Min
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Jacinta Leyden
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Zhen Wang
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
James Chang
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
,
Zhenan Bao
3   Department of Chemical Engineering, Stanford University, Stanford, California
,
Paige M. Fox 
1   Department of Surgery, Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
2   Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
› Author Affiliations Funding H.O. and P.M.F. report grants from the Plastic Surgery Foundation and the American Society for Reconstructive Microsurgery (Grant/Award Number: 570894), other from the United States Department of Veterans Affairs Rehabilitation Research and Development Service (Grant/Award Number: “Merit Review Award: I01 RX001458–01A2”) to J.C., during the conduct of the study.
Further Information

Publication History

11 June 2019

27 August 2019

Publication Date:
01 November 2019 (online)

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Abstract

Background Accurate monitoring of free flap perfusion after complex reconstruction is critical for early recognition of flap compromise. Surgeons use a variety of subjective and objective measures to evaluate flap perfusion postoperatively. However, these measures have some limitations. We have developed a wireless, biodegradable, and flexible sensor that can be applied to real-time postoperative free flap monitoring. Here we assess the biocompatibility and function of our novel sensor.

Methods Seven Sprague–Dawley (SD) rats were used for biocompatibility studies. The sensor was implanted around the femoral artery near the inguinal ligament on one leg (implant side) and sham surgery was performed on the contralateral leg (control side). At 6 and 12 weeks, samples were harvested to assess the inflammation within and around the implant and artery. Two animals were used to assess sensor function. Sensor function was evaluated at implantation and 7 days after the implantation. Signal changes after venous occlusion were also assessed in an epigastric artery island flap model.

Results In biocompatibility studies, the diameter of the arterial lumen and intima thickness in the implant group were not significantly different than the control group at the 12-week time point. The number of CD-68 positive cells that infiltrated into the soft tissue, surrounding the femoral artery, was also not significantly different between groups at the 12-week time point. For sensor function, accurate signaling could be recorded at implantation and 7 days later. A change in arterial signal was noted immediately after venous occlusion in a flap model.

Conclusion The novel wireless, biodegradable sensor presented here is biocompatible and capable of detecting arterial blood flow and venous occlusion with high sensitivity. This promising new technology could combat the complications of wired sensors, while improving the survival rate of flaps with vessel compromise due to its responsive nature.

Keywords

free flap monitoring - venous occlusion - microsurgery sensor - inflammation
 

  • References

  • 1 Disa JJ, Cordeiro PG, Hidalgo DA. Efficacy of conventional monitoring techniques in free tissue transfer: an 11-year experience in 750 consecutive cases. Plast Reconstr Surg 1999; 104 (01) 97-101
    CrossrefPubMedGoogle Scholar
  • 2 Kääriäinen M, Halme E, Laranne J. Modern postoperative monitoring of free flaps. Curr Opin Otolaryngol Head Neck Surg 2018; 26 (04) 248-253
    CrossrefPubMedGoogle Scholar
  • 3 Chae MP, Rozen WM, Whitaker IS. , et al. Current evidence for postoperative monitoring of microvascular free flaps: a systematic review. Ann Plast Surg 2015; 74 (05) 621-632
    CrossrefPubMedGoogle Scholar
  • 4 Furnas H, Rosen JM. Monitoring in microvascular surgery. Ann Plast Surg 1991; 26 (03) 265-272
    CrossrefPubMedGoogle Scholar
  • 5 Karinja SJ, Lee BT. Advances in flap monitoring and impact of enhanced recovery protocols. J Surg Oncol 2018; 118 (05) 758-767
    CrossrefPubMedGoogle Scholar
  • 6 Kroll SS, Schusterman MA, Reece GP. , et al. Timing of pedicle thrombosis and flap loss after free-tissue transfer. Plast Reconstr Surg 1996; 98 (07) 1230-1233
    CrossrefPubMedGoogle Scholar
  • 7 Bradford CR. Flap monitoring. Facial Plast Surg 1996; 12 (01) 19-21
    PubMedGoogle Scholar
  • 8 Perng CK, Ma H, Chiu YJ, Lin PH, Tsai CH. Detection of free flap pedicle thrombosis by infrared surface temperature imaging. J Surg Res 2018; 229: 169-176
    CrossrefPubMedGoogle Scholar
  • 9 Oliver DW, Whitaker IS, Giele H, Critchley P, Cassell O. The Cook-Swartz venous Doppler probe for the post-operative monitoring of free tissue transfers in the United Kingdom: a preliminary report. Br J Plast Surg 2005; 58 (03) 366-370
    CrossrefPubMedGoogle Scholar
  • 10 Paydar KZ, Hansen SL, Chang DS, Hoffman WY, Leon P. Implantable venous Doppler monitoring in head and neck free flap reconstruction increases the salvage rate. Plast Reconstr Surg 2010; 125 (04) 1129-1134
    CrossrefPubMedGoogle Scholar
  • 11 Lenz Y, Gross R, Penna V, Bannasch H, Stark GB, Eisenhardt SU. Evaluation of the implantable Doppler probe for free flap monitoring in lower limb reconstruction. J Reconstr Microsurg 2018; 34 (03) 218-226
    Article in Thieme ConnectPubMedGoogle Scholar
  • 12 Warner KG, Durham-Smith G, Butler MD, Attinger CE, Upton J, Khuri SF. Comparative response of muscle and subcutaneous tissue pH during arterial and venous occlusion in musculocutaneous flaps. Ann Plast Surg 1989; 22 (02) 108-116
    CrossrefPubMedGoogle Scholar
  • 13 Chen Y, Shen Z, Shao Z, Yu P, Wu J. Free flap monitoring using near-infrared spectroscopy: a systemic review. Ann Plast Surg 2016; 76 (05) 590-597
    CrossrefPubMedGoogle Scholar
  • 14 Koolen PG, Vargas CR, Ho OA. , et al. Does increased experience with tissue oximetry monitoring in microsurgical breast reconstruction lead to decreased flap loss? The learning effect. Plast Reconstr Surg 2016; 137 (04) 1093-1101
    CrossrefPubMedGoogle Scholar
  • 15 Salgarello M, Pagliara D, Rossi M, Visconti G, Barone-Adesi L. Postoperative monitoring of free DIEP flap in breast reconstruction with near-infrared spectroscopy: variables affecting the regional oxygen saturation. J Reconstr Microsurg 2018; 34 (06) 383-388
    Article in Thieme ConnectPubMedGoogle Scholar
  • 16 Berggren-Olsen MM, Rauff-Mortensen A, Holst R, Houlind KC, Birke-Sørensen H. Monitoring of free flaps with combined tissue spectrophotometry and laser doppler flowmetry in an animal experimental model. J Reconstr Microsurg 2017; 33 (08) 579-586
    Article in Thieme ConnectPubMedGoogle Scholar
  • 17 Hölzle F, Loeffelbein DJ, Nolte D, Wolff KD. Free flap monitoring using simultaneous non-invasive laser Doppler flowmetry and tissue spectrophotometry. J Craniomaxillofac Surg 2006; 34 (01) 25-33
    PubMedGoogle Scholar
  • 18 Boutry CM, Beker L, Kaizawa Y. , et al. Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow. Nat Biomed Eng 2019; 3 (01) 47-57
    CrossrefPubMedGoogle Scholar
  • 19 Plock JA, Schnider JT, Schweizer R. , et al. The influence of timing and frequency of adipose-derived mesenchymal stem cell therapy on immunomodulation outcomes after vascularized composite allotransplantation. Transplantation 2017; 101 (01) e1-e11
    CrossrefPubMedGoogle Scholar
  • 20 Berthelot M, Yang GZ, Lo B. A self-calibrated tissue viability sensor for free flap monitoring. IEEE J Biomed Health Inform 2018; 22 (01) 5-14
    CrossrefPubMedGoogle Scholar
  • 21 Poder TG, Fortier PH. Implantable Doppler in monitoring free flaps: a cost-effectiveness analysis based on a systematic review of the literature. Eur Ann Otorhinolaryngol Head Neck Dis 2013; 130 (02) 79-85
    CrossrefPubMedGoogle Scholar
  • 22 Kempton SJ, Poore SO, Chen JT, Afifi AM. Free flap monitoring using an implantable anastomotic venous flow coupler: analysis of 119 consecutive abdominal-based free flaps for breast reconstruction. Microsurgery 2015; 35 (05) 337-344
    CrossrefPubMedGoogle Scholar
  • 23 Chowdhury SS, Hyder R, Hafiz MSB, Haque MA. Real-time robust heart rate estimation from wrist-type ppg signals using multiple reference adaptive noise cancellation. IEEE J Biomed Health Inform 2018; 22 (02) 450-459
    CrossrefPubMedGoogle Scholar
  • 24 Huang S-C, Hung P-H, Hong C-H, Wang H-M. A new image blood pressure sensor based on PPG, RRT, BPTT, and harmonic balancing. IEEE Sens J 2014; 14 (10) 3685-3692
    CrossrefPubMedGoogle Scholar
  • 25 Chao PC, Chiang PY, Kao YH. , et al. A portable, wireless photoplethysomography sensor for assessing health of arteriovenous fistula using class-weighted support vector machine. Sensors (Basel) 2018; 18 (11) E3854
    CrossrefPubMedGoogle Scholar
  • 26 Chiang P-Y, Chao PC-P, Tarng D-C, Yang C-Y. A novel wireless photoplethysmography blood-flow volume sensor for assessing arteriovenous fistula of hemodialysis patients. IEEE Trans Ind Electron 2017; 64 (12) 9626-9635
    CrossrefPubMedGoogle Scholar
  • 27 Kind GM, Buntic RF, Buncke GM, Cooper TM, Siko PP, Buncke Jr HJ. The effect of an implantable Doppler probe on the salvage of microvascular tissue transplants. Plast Reconstr Surg 1998; 101 (05) 1268-1273 , discussion 1274–1275
    CrossrefPubMedGoogle Scholar