Thorac Cardiovasc Surg 2013; 61(08): 656-662
DOI: 10.1055/s-0032-1311549
Original Basic Science
Georg Thieme Verlag KG Stuttgart · New York

Preservation of Endothelial Vascular Function of Saphenous Vein Grafts after Long-Time Storage with a Recently Developed Potassium-Chloride and N-Acetylhistidine Enriched Storage Solution

Manuel Wilbring
1   Department for Cardiac Surgery, University Heart Center Dresden, Dresden, Germany
,
Sems Malte Tugtekin
1   Department for Cardiac Surgery, University Heart Center Dresden, Dresden, Germany
,
Birgit Zatschler
2   Institute for Physiology, Medical Faculty ‘Carl Gustav Carus’ Dresden, Dresden, Germany
,
Annette Ebner
2   Institute for Physiology, Medical Faculty ‘Carl Gustav Carus’ Dresden, Dresden, Germany
,
Hermann Reichenspurner
3   Department for Cardiovascular Surgery, University Heart Center, Hamburg, Germany
,
Utz Kappert
1   Department for Cardiac Surgery, University Heart Center Dresden, Dresden, Germany
,
Klaus Matschke
1   Department for Cardiac Surgery, University Heart Center Dresden, Dresden, Germany
,
Andreas Deussen
2   Institute for Physiology, Medical Faculty ‘Carl Gustav Carus’ Dresden, Dresden, Germany
› Author Affiliations
Further Information

Publication History

19 December 2011

16 February 2012

Publication Date:
12 July 2012 (online)

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Abstract

Objectives Saphenous vein grafts are still commonly used in cardiac, vessel and also in transplant surgery. In cardiac surgery, a desperate graft situation could force to keep nonutilized explanted vein segments after CABG in reserve for case of early graft failure. Historically there were no options for adequate long-time graft storage protecting the endothelial layer with its important antithrombotic and immunosuppressive functional aspects. Commonly isotonic saline solution (sodium chloride [NaCl]) has been used as a storing solution in this case. We investigated the impact of long-time storage in NaCl and a recently developed potassium-chloride and N-acetylhistidine enriched storage solution (TiProtec, Dr. Köhler Chemie, Germany) on endothelial function of saphenous veins.

Methods Saphenous vein segments (n = 19) were intraoperatively isolated and stored for 24 and 96 hours. The segments were examined in a Mulvany-myograph to assess vessel function. Following preconstriction with norepinephrine, dose–response curves were assessed for relaxation with bradykinin and sodium-nitroprusside. We compared developed maximum wall tension and endothelial cell and smooth muscle cell (SMC) dependent vasodilatory function.

Results Maximum vessel wall tension was significantly better preserved in TiProtec-stored vessels after 24 h in comparison to segments stored in NaCl (5.11 ± 4.79 mN/mm vs. 2.48 ± 2.43 mN/mm; p = 0.033) and 96 h (4.94 ± 2.82 mN/mm vs. 2.80 ± 1.76 mN/mm; p = 0.042). Likewise endothelium-derived vasodilatory function was maintained significantly after 24 hours in TiProtec-stored vessels (36.9 ± 2.6% vs. 11.8 ± 30.9%; p = 0.005). After 96 hours, endothelium-dependent vascular function was nearly abolished in NaCl-stored vessels, but largely preserved in TiProtec-stored segments (20.6 ± 2.9% vs. 1.9 ± 4.3% in NaCl; p = 0.015). Sodium nitroprusside–mediated SMC-vasodilatory function was better maintained after 24 hours of storage in TiProtec group (88.8 ± 6.4% vs. 61.3 ± 8.2%; p = 0.009). After 96 hours of storage, SMC relaxation did not significantly differ between both storage groups which might be due to a distinct reduction of contractile function in NaCl-stored vessels (98.6 ± 5.0% and 77.9 ± 10.5% for Tiprotec and NaCl, respectively).

Conclusion Vessel functions comprising contraction, endothelium-dependent and -independent vasodilatation are significantly reduced following 24 hours of cold storage in NaCl. After 96 hours of storage in NaCl these functions are nearly totally abolished. TiProtec is able to largely reduce this loss of function during cold storage. Therefore, TiProtec is a feasible option for longer term storage of saphenous vein grafts in CABG vessel and transplant surgery.