Imaging characteristics, and long term outcomes of surgical management for pannus overgrowth after mechanical aortic valve replacement

Van Hung Dung

Main Article Content

Abstract

Background: Endocardial proliferation or pannus is uncommon after aortic valve replacement. This study aimed to determine the imaging characteristics, the risk factors and evaluate the long-term results of surgical treatment for these patients.


Material and methods: a retrospective review of patients with confirmed intraoperative pannus diagnosis following mechanical aortic replacement.


Results: There have 102 patients (mean age 48 and 71 women) who were re-operated for pannus. The image of “pannus” seen on echocardiography and valve dysfunction on fluoroscopy is positive in over 90% of cases. Female sex (OR=2.1, P=0.01) and both aortic and mitral valve replacement at first surgery (OR=2.98; P = 0.001) have a higher risk of pannus. Surgical procedures included pannus resection only or aortic replacement with a new valve and resect pannus or resect pannus, aortic replacement with aortic annulus enlargement. 30-day mortality was 1 case; atrioventricular block required permanent pace marker: 2 cases. The mean follow-up time for the second operation was 55.3 ± 48.8 months (2 cases lost of follow-up), recurrent pannus occurred in 5 cases, and no late death.


Conclusion: The female patients and previously aortic combined with mitral replacement are a risks factor for pannus.  Echocardiography combined with fluoroscopy could be identified as the diagnosis of pannus. The long-term outcomes of surgery for pannus are very good. Completely resect the pannus and replace it with the new valve is the method of choice instead of simply resecting the pannus to prevent recurrent pannus.

Article Details

References

1. Akins CW, Miller DC, Turina MI, Kouchoukos NT, Blackstone EH, Grunkemeier GL, et al. Guidelines for reporting mortality and morbidity after cardiac valve interventions. Euro J Cardiothorac Surg 2008; 33: 523-528.
2. Sakamoto Y, Hashimoto K, Okuyama H, Ishii S, Shingo T, Kagawa H. Prevalence of pannus formation after aortic valve replacement: clinical aspects and surgical management. J Artif Organs 2006; 9:199–202.
3. Teshima H, Hayashida N, Yano H, Nishimi M, Tayama E, Fukunaga S, et al. Obstruction of St Jude Medical valves in the aortic position: Histology and immunohistochemistry of pannus. J Thorac Cardiovasc Surg 2003;126: 401-7.
4. Ozkan M, Gunduz S, Yildız M, and Eksi Duran N. Diagnosis of the prosthetic heart valve pannus formation with real-time three-dimensional transoesophageal echocardiography. Euro J Echocardiograp 2010; 11, E17.doi:10.1093/ ejechocard /jep206.
5. Lancellotti P, Pibarot P, Chambers J, Edvardsen T, Delgado V, Dulgheru R, et al. Recommendations for the imaging assessment of prosthetic heart valves: a report from the European Association of Cardiovascular Imaging Endorsed by the Chinese Society of Echocardiography, the Inter-American Society of Echocardiography, and the Brazilian Department of Cardiovascular Imaging. ESC 2016- Euro Heart J Cardiovascular Imaging doi:10.1093/ ehjci/ jew025.
6. Ellensen VS, Andersen KS, Vitale N, et al. Acute obstruction by pannus in patients with aortic Medtronic-hall valves: 30 years of experience. Ann Thorac Surg 2013; 96:2123-8.
7. Park PW, Park B, Jeong DS, et al. Clinical outcomes of repeat aortic valve replacement for subaortic pannus in the mechanical aortic valve. Circ J. 2018; 82(10):2535-41.
8. Rizzoli G, Guglielmi C, Toscano G, Pistorio V, Vendramin I, Bottio T, et al. Re-operations for acute prosthetic thrombosis and pannus: an assessment of rates, relationship and risk. Eur J Cardiothorac Surg 1999; 16: 74-80.
9. Han K, Yang DH, Shin SY, Kim N et al. Subprosthetic Pannus after Aortic Valve Replacement Surgery: Cardiac CT Findings and Clinical Features. Radiology: September 2015, Volume 276: Number 3