Tissue-Disruptive Forces during Median Sternotomy


  • Gil Bolotin
  • Gregory D. Buckner
  • Nigel B. Campbell
  • B. vet
  • Masha Kocherginsky
  • Jai Raman
  • Valluvan Jeevanandam
  • Jos G. Maessen




Background. Acute and chronic pain after median sternotomy is common and often underestimated. The mechanical retractors used for median sternotomy exert significant forces on the skeletal cage. We hypothesized that instrumented retractors could be developed to enable real-time monitoring and control of retraction forces, functions that may provide equivalent exposure with significantly reduced forces and tissue damage, and thus, less postoperative pain.

Methods. We developed a novel instrumented retractor designed to enable real-time force monitoring during surgical retraction and then tested it by performing median sternotomies on 16 mature sheep. For 8 of these median sternotomies, retraction was performed to 7.5 cm at a standard "clinical pace" of 7.25 ± 0.97 minutes without real-time monitoring of retraction forces. For the other 8 median sternotomies, we performed retraction to the same exposure using real-time visual force feedback and, consequently, a more deliberate pace of 12.05 ± 1.73 minutes (P <.001). Retraction forces, blood pressure, and heart rate were monitored throughout the procedure.

Results. Full retraction resulted in an average force of 102.99 ± 40.68 N at the standard clinical pace, compared to 64.68 ± 17.60 N with force feedback (a 37.2% reduction, P = .021). Standard retraction produced peak forces of 368.79 ± 133.61 N, whereas force feedback yielded peak forces of 254.84 ± 75.77 N (a 30.9% reduction, P = .1152). Heart rate was significantly higher during standard clinical retraction (P = .025).

Conclusions. Use of the novel instrumented retractor resulted in lower average and peak retraction forces during median sternotomy. Moreover, these reduced retraction forces correlated to a reduction in animal stress, as documented by heart rate.


Baisden CE, Greenwald LV, Symbas PN. 1984. Occult rib fractures and brachial plexus injury following median sternotomy for open-heart operations. Ann Thorac Surg 38:192-4.nBolotin G, Buckner GD, Jardine NJ, et al. 2007. A novel instrumented retractor to monitor tissue-disruptive forces during lateral thoracotomy. J Thorac Cardiovasc Surg 133:949-54.nBruce J, Drury N, Poobalan AS, Jeffrey RR, Smith WC, Chambers WA. 2003. The prevalence of chronic chest and leg pain following cardiac surgery: a historical cohort study. Pain 104:265-73.nCanbaz S, Turgut N, Halici U, Sunar H, Balci K, Duran E. 2005. Brachial plexus injury during open heart surgery: controlled prospective study. Thorac Cardiovasc Surg 53:295-9.nCurtis JA, Libshitz HI, Kalinka MK. 1975. Fracture of the first rib as a complication of midline sternotomy. Radiology 115:63-5.nEisenberg E, Pultorak Y, Pud D, Bar-El Y. 2001. Prevalence and characteristics of post coronary artery bypass graft surgery pain (PCP). Pain 92:11-7.nEl Solh AA, Bhora M, Pineda L, Dhillon R. 2006. Nosocomial pneumonia in elderly patients following cardiac surgery. Respir Med 100:729-36.nGotoda Y, Kambara N, Sakai T, Kishi Y, Kodama K, Koyama T. 2001. The morbidity, time course and predictive factors for persistent postthoracotomy pain. Eur J Pain 5:89-96.nGumbs RV, Peniston RL, Nabhani HA, Henry LJ. 1991. Rib fractures complicating median sternotomy. Ann Thorac Surg 51:952-5.nHazelrigg SR, Cetindag IB, Fullerton J. 2002. Acute and chronic pain syndromes after thoracic surgery. Surg Clin North Am 82:849-65.nJellish WS, Martucci J, Blakeman B, Hudson E. 1994. Somatosensory evoked potential monitoring of the brachial plexus to predict nerve injury during internal mammary artery harvest: intraoperative comparisons of the Rultract and Pittman sternal retractors. J Cardiothorac Vasc Anesth 8:398-403.nJellish WS, Blakeman B, Warf P, Slogoff S. 1997. Hands-up positioning during asymmetric sternal retraction for internal mammary artery harvest: a possible method to reduce brachial plexus injury. Anesth Analg 84:260-5.nKalso E, Mennander S, Tasmuth T, Nilsson E. 2001. Chronic poststernotomy pain. Acta Anaesthesiol Scand 45:935-9.nMeyerson J, Thelin S, Gordh T, Karisten R. 2001. The incidence of chronic post-sternotomy pain after cardiac surgery: a prospective study. Acta Anaesthesiol Scand 45:940-4.nMoore R, Follette DM, Berkoff HA. 1994. Poststernotomy fractures and pain management in open cardiac surgery. Chest 106:1339-42.nNational Academy of Sciences (NAS). 1985. Guide for the Care and Use of Laboratory Animals. DHHS Publication No. NIH 85-23.nPerttunen K, Tasmuth T, Kalso E. 1999. Chronic pain after thoracic surgery: a follow-up study. Acta Anaesthesiol Scand 43:563-7.nRogers ML, Duffy JP. 2000. Surgical aspects of chronic post-thoracotomy pain. Eur J Cardiothorac Surg 18:711-6.nSeyfer AE, Grammer NY, Bogumill GP, Provost JM, Chandry U. 1985. Upper extremity neuropathies after cardiac surgery. J Hand Surg (Am) 10:16-9.nWoodring JH, Royer JM, Todd EP. 1985. Upper rib fractures following median sternotomy. Ann Thorac Surg 39:355-7.n



How to Cite

Bolotin, G., Buckner, G. D., Campbell, N. B., vet, B., Kocherginsky, M., Raman, J., Jeevanandam, V., & Maessen, J. G. (2007). Tissue-Disruptive Forces during Median Sternotomy. The Heart Surgery Forum, 10(6), E487-E492. https://doi.org/10.1532/HSF98.20071121




Most read articles by the same author(s)