Title: Physiologic left ventricular reconstruction: Shape, function, and time recaptured
Abstract: Central MessageSuccessful long-term reconstruction of a failing dilated heart by recapturing normal helical form and torsion function, and showing time-related improvement. Rebuilding form is a surgical guidepost.See Article page 382. Successful long-term reconstruction of a failing dilated heart by recapturing normal helical form and torsion function, and showing time-related improvement. Rebuilding form is a surgical guidepost. See Article page 382. The surgical goal of recapturing normality is emphasized by Cirillo and colleagues 1 in their report of time analysis of physiologic left ventricular (LV) reconstruction, as his database on surgical ventricular restoration shows 0% hospital mortality and no worsening heart failure symptoms 7.9 years post operatively in patients with ischemic cardiomyopathy. The power of this study lies in addressing normality, recognizing its disruption by disease, and then rebuilding the normal ventricular ellipse. Anatomy is the highlight. The objective is to restore the helical framework, which becomes spherical with heart failure.2Buckberg G. Hoffman J.I. Mahajan A. Saleh S. Coghlan C. Cardiac mechanics revisited: the relationship of cardiac architecture to ventricular function.Circulation. 2008; 118: 2571-2587Crossref PubMed Scopus (273) Google Scholar, 3Buckberg G.D. Hoffman J.I. Coghlan H.C. Nanda N.C. Ventricular structure-function relations in health and disease, part II: clinical considerations.Eur J Cardiothorac Surg. 2015; 47: 778-787Crossref PubMed Scopus (33) Google Scholar The Fontan suture is not done, but a resulting conical form is demonstrated. Attaining this shape sets the stage for placing a longitudinal suture line using a narrow patch extending from the apex to the septum (just beneath the aortic valve). The terminal upper point may contain either normal muscle or scar tissue (which may end in the lower septum).4Buckberg G.D. Editorial comment: surgical planning for surgical ventricular restoration involves decision options on form versus disease.Eur J Cardiothorac Surg. 2010; 37: 1100-1103Crossref PubMed Scopus (2) Google Scholar Restoration of form, not merely disease exclusion, has become a surgical goal. Isomura and associates5Isomura T. Hoshino J. Fukada Y. Kitamura A. Katahira S. Kondo T. et al.Volume reduction rate by surgical ventricular restoration determines late outcome in ischaemic cardiomyopathy.Eur J Heart Fail. 2011; 13: 423-431Crossref PubMed Scopus (40) Google Scholar demonstrated the importance of rebuilding shape versus simply reducing LV size, reporting an 86% 8-year survival rate in patients with hearts of the same size as in the study of Cirillo and colleagues,1Cirillo M. Campana M. Brunelli F. Dalla T.M. Mhagna Z. Messina A. et al.Time series analysis of physiologic left ventricular reconstruction in ischemic cardiomyopathy.J Thorac Cardiovasc Surg. 2016; 152: 382-391Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar and an overall long-term survival of 72% versus 61% with a “shape” yardstick. The second strength is restoring ventricular function, as measured by returning cardiac torsion… with one helical arm rotating clockwise (base) and the other counterclockwise (apex). Finally, the role of time is addressed. Surgical reconstruction changes anatomy, but adequate time is needed to rebuild the previously stretched collagen of a spherical heart, whose matrix metalloproteinase half-life is >120 days.6Caulfield J.B. Janicki J.S. Structure and function of myocardial fibrillar collagen.Technol Health Care. 1997; 5: 95-113Crossref PubMed Google Scholar Cirillo's results by returning normal shape differed from the flawed STICH trial, where the pre operative spherical shape was unchanged.7Choi J.O. Daly R.C. Lin G. Lahr B.D. Wiste H.J. Beaver T.M. et al.Impact of surgical ventricular reconstruction on sphericity index in patients with ischaemic cardiomyopathy: follow-up from the STICH trial.Eur J Heart Fail. 2015; 17: 453-463Crossref PubMed Scopus (21) Google Scholar They concluded that LV reconstruction is not different from CABG, yet lowered LV volume falls 19% (vs 51% here).8Michler R.E. Rouleau J.L. Al-Khalidi H.R. Bonow R.O. Pellikka P.A. Pohost G.M. et al.STICH Trial Investigators. Insights from the STICH trial: change in left ventricular size after coronary artery bypass grafting with and without surgical ventricular reconstruction.J Thorac Cardiovasc Surg. 2013; 146: 1139-1145Abstract Full Text Full Text PDF PubMed Scopus (120) Google Scholar Consequently, STICH deprived many patients of a sound procedure because of its improper patient selection and inadequate surgical expertise.9Buckberg G. Athanasuleas C. Conte J. Surgical ventricular restoration for the treatment of heart failure.Nat Rev Cardiol. 2012; 9: 703-716Crossref PubMed Scopus (34) Google Scholar First, a role for a wider patch should be considered when LV reconstruction is done before remote muscle is stretched, for example, early after myocardial infarction. This would avoid producing a restrictive LV size when excluding the scar. Second, inclusion of the sphericity index (ventricular length/width) would document a spherical chamber preoperatively, and confirm postoperative physiologic reconstruction. Finally, all recovery occurs at the apex, because the base rotates only marginally. Where are comparative normal base values, and what was the mitral annulus width? Could this imply that the base should be narrowed by an annular ring? This splendid study emphasizes our responsibility for rebuilding normal anatomy and function. These endpoints require an understanding of the guideposts of normality. The mechanics of the twisting motion for torsion call for LV rebuilding that restores the natural form and prevents intraoperative muscular injury from inadequate cardiac protection. When achieved, these vital form and function endpoints are reproducible, and cannot be offset by the flawed prospective randomized STICH Trial, which reports noncredible data. Time series analysis of physiologic left ventricular reconstruction in ischemic cardiomyopathyThe Journal of Thoracic and Cardiovascular SurgeryVol. 152Issue 2PreviewThe history of left ventricular reconstruction has demonstrated that the full spectrum of recoverable physiologic parameters is essential for a good functional result. We report the long-term outcome of a new surgical technique that arranges myocardial fibers in a near-normal disposition, also recovering left ventricular twisting. Full-Text PDF Open Archive