A Concentric Tube Robot System for Rigid Bronchoscopy: A Feasibility Study on Central Airway Obstruction Removal


New robotic systems have recently emerged to assist with peripheral lung access, but a robotic system for rigid bronchoscopy has yet to be developed. We describe a new robotic system that can deliver thin robotic manipulators through the ports of standard rigid bronchoscopes. The manipulators bend and elongate to provide maneuverability of surgical tools at the endoscope tip, without endoscope motion. We describe an initial feasibility study on the use of this system to bronchoscopically treat a central airway obstruction (CAO). CAO is prevalent and can be life-threatening in patients with large tumors, and conventional rigid bronchoscopic treatments place patients at risk of complications including broken teeth, neck trauma and damage to oropharyngeal structures due to significant forces induced by bronchoscope tilting and manipulation. In this study, we used an ex vivo ovine airway model to demonstrate the ability of a physician using the robotic system to efficiently remove tissue and restore the airway. Pre- and post-operative CT scans showed that the robot was able to reduce the degree of airway obstruction stenosis from 75 to 14% on average for five CAO resections performed in an ex vivo animal model. Using cadaver experiments, we demonstrated the potential of the robotic system to substantially reduce the intraoperative forces applied to the patient’s head and neck (from 80.6 to 4.1 N). These preliminary results illustrate that CAO removal is feasible with our new rigid bronchoscopy robot system, and that this approach has the potential to reduce forces applied to the patient due to bronchoscope angulation, and thereby reduce the risk of complications encountered during CAO surgery.

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  1. 1.

    Breatnach, E., G. Abbott, and R. Fraser. Dimensions of the normal human trachea. Am. J. Roentgenol. 142:903–906, 1984.

  2. 2.

    Brichet, A., C. Verkindre, J. Dupont, M. Carlier, J. Darras, A. Wurtz, P. Ramon, and C. Marquette. Multidisciplinary approach to management of postintubation tracheal stenoses. Eur. Respir. J. 13:888–893, 1999.

  3. 3.

    Brodie, A. and N. Vasdev. The future of robotic surgery. Robotics 100:4–13, 2018.

  4. 4.

    Casal, R. F., J. Iribarren, G. Eapen, D. Ost, R. Morice, C. Lan, L. Cornwell, F. A. Almeida, H. Grosu, and C. A. Jimenez. Safety and effectiveness of microdebrider bronchoscopy for the management of central airway obstruction. Respirology 18:1011–1015, 2013.

  5. 5.

    Chan, E. Malignant airway obstruction: treating central airway obstruction in the oncologic setting. UWOMJ 80:7–9, 2011.

  6. 6.

    Chan, J. Y. K., E. W. Y. Wong, R. K. Tsang, F. C. Holsinger, M. C. F. Tong, P. W. Y. Chiu, and S. S. M. Ng. Early results of a safety and feasibility clinical trial of a novel single – port flexible robot for transoral robotic surgery. Eur. Arch. Otorhinolaryngol. 274:3993–3996, 2017.

  7. 7.

    Chen, C., J. P. Bent, and S. R. Parikh. Powered debridement of suprastomal granulation tissue to facilitate pediatric tracheotomy decannulation. Int. J. Pediatr. Otorhinolaryngol. 75:1558–1561, 2011.

  8. 8.

    Chen, K., M. Joseph Varon, O. C. Wenker, et al. Malignant airway obstruction: recognition and management. J. Emerg. Med. 16:83–92, 1998.

  9. 9.

    Chhajed, P. N., F. Baty, M. Pless, S. Somandin, M. Tamm, and M. H. Brutsche. Outcome of treated advanced non-small cell lung cancer with and without central airway obstruction. Chest 130:1803–1807, 2006.

  10. 10.

    Ernst, A., D. Feller-Kopman, H. D. Becker, and A. C. Mehta. Central airway obstruction. Am. J. Respir. Crit. Care Med. 169:1278–1297, 2004.

  11. 11.

    Fedorov, A., R. Beichel, J. Kalpathy-Cramer, J. Finet, J.-C. Fillion-Robin, S. Pujol, C. Bauer, D. Jennings, F. Fennessy, M. Sonka, J. Buatti, S. Aylward, J. V. Miller, S. Pieper, and R. Kikinis. 3d slicer as an image computing platform for the quantitative imaging network. Magn. Reason. Imaging 30:1323 – 1341, 2012. Quantitative Imaging in Cancer.

  12. 12.

    Feins, R. H., H. M. Burkhart, J. V. Conte, D. N. Conte, J. I. Fann, G. L. Hicks, J. C. Nesbitt, P. S. Ramphal, S. E. Schiro, K. R. Shen, et al. Simulation-based training in cardiac surgery. Ann. Thorac. Surg. 103:312–321, 2017.

  13. 13.

    Gilbert, H. B., D. C. Rucker, and R. J. Webster III. Concentric tube robots: the state of the art and future directions. Robot Res.. 114:253–269, 2016.

  14. 14.

    Ginsberg, R., E. Vokes, and A. Raben. Non-small cell lung cancer. In: Cancer: Principles and Practice of Oncology. Philadelphia: Lippincott Williams and Wilkins, 1997, pp. 858–910.

  15. 15.

    Gompelmann, D., R. Eberhardt, and F. Herth. Novel endoscopic approaches to treating chronic obstructive pulmonary disease and emphysema. In: Seminars in Respiratory and Critical Care Medicine, volume 36, pp. 609–615. Noida: Thieme Medical Publishers, 2015.

  16. 16.

    Hans, S., B. Delas, P. Gorphe, M. Ménard, and D. Brasnu. Transoral robotic surgery in head and neck cancer. Eur. Ann. Otorhinolaryngol. Head Neck Dis. 129:32–37, 2012.

  17. 17.

    Hendrick, R. J., C. R. Mitchell, S. D. Herrell, and R. J. W. Iii. Hand-held transendoscopic robotic manipulators: a transurethral laser prostate surgery case study. Int. J. Robot Res. 34:1559–1572, 2016.

  18. 18.

    Hohenforst-Schmidt, W., P. Zarogoulidis, G. Pitsiou, B. Linsmeier, D. Tsavlis, I. Kioumis, E. Papadaki, L. Freitag, T. Tsiouda, J. F. Turner, et al. Drug eluting stents for malignant airway obstruction: a critical review of the literature. J. Cancer 7:377, 2016.

  19. 19.

    Ingenito, E. P., D. E. Wood, and J. P. Utz. Bronchoscopic lung volume reduction in severe emphysema. Proc. Am. Thorac. Soc. 5:454–460, 2008.

  20. 20.

    Kumar, A. and B. B. Asaf. Robotic thoracic surgery: the state of the art. J. Minim. Access Surg. 11:60, 2015.

  21. 21.

    Mahmood, K. and M. M. Wahidi. Ablative therapies for central airway obstruction. Semin. Respir. Crit. Care Med. 35:681–692, 2014.

  22. 22.

    Mahoney, A. W., H. B. Gilbert, and R. J. Webster. Chapter 7: A review of concentric tube robots: modeling, control, design, planning, and sensing. In: The Encyclopedia of Medical Robotics, volume 1, pp. 181–202. Singapore: World Scientific, 2018.

  23. 23.

    Makris, K. I., E. Rieder, and L. L. Swanstrom. Natural Orifice Trans-Luminal Endoscopic Surgery (NOTES) in thoracic surgery. Semin. Thorac. Cardiovasc. Surg. 22:302–309, 2010.

  24. 24.

    Maloney, J. D., T. L. Weigel, and R. B. Love. Endoscopic repair of bronchial dehiscence after lung transplantation. Ann. Thorac. Surg. 72:2109–2111, 2001.

  25. 25.

    Mattheis, S., P. Hasskamp, L. Holtmann, C. Sch, U. Geisthoff, N. Dominas, and S. Lang. Flex robotic system in transoral robotic surgery: the first 40 patients. Head Neck 39: 471–475, 2017.

  26. 26.

    McDougall, J. and D. Cortese. Neodymium–YAG laser therapy of malignant airway obstruction. a preliminary report. In: Mayo Clinic Proceedings, volume 58, pp. 35–39. 1983.

  27. 27.

    Mineshita, M. and D.-J. Slebos. Bronchoscopic interventions for chronic obstructive pulmonary disease. Respirology 19:1126–1137, 2014.

  28. 28.

    Mokadam, N. A., J. I. Fann, G. L. Hicks, J. C. Nesbitt, H. M. Burkhart, J. V. Conte, D. N. Coore, P. S. Ramphal, K. R. Shen, J. D. Walker, et al. Experience with the cardiac surgery simulation curriculum: results of the resident and faculty survey. Ann. Thorac. Surg. 103:322–328, 2017.

  29. 29.

    Mudambi, L., R. Miller, and G. A. Eapen. Malignant central airway obstruction. J. Thorac. Dis. 9:S1087, 2017.

  30. 30.

    Murgu, S. and H. G. Colt. Morphometric bronchoscopy in adults with central airway obstruction: case illustrations and review of the literature. Laryngoscope 119:1318–1324, 2009.

  31. 31.

    Murgu, S. and H. Colt. Subjective assessment using still bronchoscopic images misclassifies airway narrowing in laryngotracheal stenosis. Interact. Cardiovasc. Thorac. Surg. 16:655–660, 2013.

  32. 32.

    Nicastri, D. G. and T. S. Weiser. Rigid bronchoscopy: indications and techniques. YOTCT 17:44–51, 2012.

  33. 33.

    Nouraei, S. A., K. V. Kapoor, S. M. Nouraei, K. Ghufoor, D. J. Howard, and G. S. Sandhu. Results of endoscopic tracheoplasty for treating tracheostomy-related airway stenosis. Clin. Otolaryngol. 32:471–475, 2007.

  34. 34.

    Ost, D. E., A. Ernst, H. B. Grosu, X. Lei, J. Diaz-Mendoza, M. Slade, T. R. Gildea, M. S. Machuzak, C. A. Jimenez, J. Toth, et al.Therapeutic bronchoscopy for malignant central airway obstruction. Chest 147:1282–1298, 2015.

  35. 35.

    Pathak, V., I. Welsby, K. Mahmood, M. Wahidi, N. Macintyre, and S. Shofer. Ventilation and anesthetic approaches for rigid bronchoscopy. Ann. Am. Thorac. Soc. 11:628–634, 2014.

  36. 36.

    Raman, T., K. Chatterjee, B. N. Alzghoul, A. A. Innabi, O. Tulunay, T. Bartter, and N. K. Meena. A bronchoscopic approach to benign subglottic stenosis. SAGE Open Med. Case Rep. 5:2050313X1771315, 2017.

  37. 37.

    Remacle, M., V. Prasad, G. Lawson, L. Plisson, V. Bachy, and S. V. D. Vorst. Transoral robotic surgery (TORS) with the Medrobotics Flex System: first surgical application on humans. Eur. Arch. Otorhinolaryngol. 272:1451–1455, 2015.

  38. 38.

    Schuler, P. J., T. K. Hoffmann, J. A. Veit, D. T. Friedrich, and M. O. Scheithauer. Hybrid procedure for total laryngectomy with a flexible robot-assisted surgical system. Int. J. Med. Robot. Comput. Assist. Surg. 13:1–7, 2017.

  39. 39.

    Stahl, D., K. Richard, and T. Papadimos. Complications of bronchoscopy: a concise synopsis. Int. J. Crit. Illn. Inj. Sci. 5:189–195, 2015.

  40. 40.

    Stratakos, G., V. Gerovasili, C. Dimitropoulos, I. Giozos, F. T. Filippidis, S. Gennimata, P. Zarogoulidis, A. Zissimopoulos, A. Pataka, N. Koufos, et al. Survival and quality of life benefit after endoscopic management of malignant central airway obstruction. J. Cancer 7:794, 2016.

  41. 41.

    Toma, T. P., N. S. Hopkinson, J. Hillier, D. M. Hansell, C. Morgan, P. G. Goldstraw, M. I. Polkey, and D. M. Geddes. Bronchoscopic volume reduction with valve implants in patients with severe emphysema. Lancet 361:931–933, 2003.

  42. 42.

    Vishwanath, G., K. Madan, A. Bal, A. N. Aggarwal, D. Gupta, and R. Agarwal. Rigid bronchoscopy and mechanical debulking in the management of central airway tumors: an indian experience. J. Bronchol. Interv. Pulmonol. 20:127–133, 2013.

  43. 43.

    Williamson, J., M. Phillips, D. Hillman, and P. Eastwood. Managing obstruction of the central airways. Intern. Med. J 40:399–410, 2010.

  44. 44.

    Yang, B., F. Zhao, Z. Zong, J. Yuan, X. Song, M. Ren, Q. Meng, G. Dai, F. Kong, S. Xie, et al. Preferences for treatment of lobectomy in chinese lung cancer patients: video-assisted thoracoscopic surgery or open thoracotomy? Patient Prefer. Adher. 8:1393, 2014.

  45. 45.

    Zhang, L. and S. Gao. Robot-assisted thoracic surgery versus open thoracic surgery for lung cancer: a system review and meta-analysis. Int. J. Clin. Exp. Med. 8:17804, 2015.

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The authors thank the National Institutes of Health (NIH) Small Business Technology Transfer (STTR) for Grant R41 HL140709 which supported the work described in this paper. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Institutes of Health.

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Correspondence to Joshua B. Gafford.

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Conflict of interest

The authors have reported to Annals of Biomedical Engineering the following conflicts of interest: The robot concept described in this paper originated in R.W.’s laboratory at Vanderbilt University, and is in the early stages of technology transfer to a startup company, Virtuoso Surgical, Inc., created for purposes of bringing this technology to market, under a Phase I STTR grant from the National Institutes of Health. S.W., N.D., E.B., R.H., D.H. and R.W. are equity holders in Virtuoso. S.W., N.D., E.B. and R.H. are employed by Virtuoso. R.W. and R.H. are founders and board members of Virtuoso, with R.W. serving as president and R.H. serving as Chief Operating Officer. The robot described in this paper is an early-stage prototype, and has not yet begun to go through the FDA approval process. It is not cleared for human use or available for purchase. It will undergo a number of extensive design revisions before becoming a commercial product.

Ethical Approval

All experiments were performed by a single interventional pulmonologist (F.M.). We did not recruit a multiple-user cohort for these proof-of-concept experiments. Based on this consideration, and the fact that no patients or live animals were involved in our experiments, prior approval from an ethics committee (IRB or IACUC) was not required.

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Gafford, J.B., Webster, S., Dillon, N. et al. A Concentric Tube Robot System for Rigid Bronchoscopy: A Feasibility Study on Central Airway Obstruction Removal. Ann Biomed Eng 48, 181–191 (2020).

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  • Central Airway Obstruction
  • Bronchoscopy
  • Robotics