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

  • Joshua B. GaffordEmail author
  • Scott Webster
  • Neal Dillon
  • Evan Blum
  • Richard Hendrick
  • Fabien Maldonado
  • Erin A. Gillaspie
  • Otis B. Rickman
  • S. Duke Herrell
  • Robert J. WebsterIII


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.


Central Airway Obstruction Bronchoscopy Robotics 



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.

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.

Supplementary material

Supplementary material 1 (MP4 16686 kb)


  1. 1.
    Breatnach, E., G. Abbott, and R. Fraser. Dimensions of the normal human trachea. Am. J. Roentgenol. 142:903–906, 1984.CrossRefGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  3. 3.
    Brodie, A. and N. Vasdev. The future of robotic surgery. Robotics 100:4–13, 2018.Google Scholar
  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.CrossRefPubMedGoogle Scholar
  5. 5.
    Chan, E. Malignant airway obstruction: treating central airway obstruction in the oncologic setting. UWOMJ 80:7–9, 2011.Google Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.Google Scholar
  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.Google Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  20. 20.
    Kumar, A. and B. B. Asaf. Robotic thoracic surgery: the state of the art. J. Minim. Access Surg. 11:60, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  21. 21.
    Mahmood, K. and M. M. Wahidi. Ablative therapies for central airway obstruction. Semin. Respir. Crit. Care Med. 35:681–692, 2014.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.Google Scholar
  27. 27.
    Mineshita, M. and D.-J. Slebos. Bronchoscopic interventions for chronic obstructive pulmonary disease. Respirology 19:1126–1137, 2014.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  29. 29.
    Mudambi, L., R. Miller, and G. A. Eapen. Malignant central airway obstruction. J. Thorac. Dis. 9:S1087, 2017.CrossRefPubMedPubMedCentralGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  32. 32.
    Nicastri, D. G. and T. S. Weiser. Rigid bronchoscopy: indications and techniques. YOTCT 17:44–51, 2012.Google Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  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.CrossRefPubMedPubMedCentralGoogle Scholar
  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.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  43. 43.
    Williamson, J., M. Phillips, D. Hillman, and P. Eastwood. Managing obstruction of the central airways. Intern. Med. J 40:399–410, 2010.CrossRefPubMedGoogle Scholar
  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.CrossRefGoogle Scholar
  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.PubMedPubMedCentralGoogle Scholar

Copyright information

© Biomedical Engineering Society 2019

Authors and Affiliations

  • Joshua B. Gafford
    • 1
    • 4
    Email author
  • Scott Webster
    • 2
  • Neal Dillon
    • 2
  • Evan Blum
    • 2
  • Richard Hendrick
    • 2
  • Fabien Maldonado
    • 1
    • 3
    • 4
  • Erin A. Gillaspie
    • 3
    • 4
  • Otis B. Rickman
    • 3
    • 4
  • S. Duke Herrell
    • 1
    • 2
    • 3
    • 4
  • Robert J. WebsterIII
    • 1
    • 2
    • 3
    • 4
  1. 1.Mechanical Engineering DepartmentVanderbilt UniversityNashvilleUSA
  2. 2.Virtuoso Surgical, Inc.NashvilleUSA
  3. 3.Vanderbilt University Medical CenterNashvilleUSA
  4. 4.Vanderbilt Institute for Surgery and Engineering (VISE)NashvilleUSA

Personalised recommendations