Effects of papaverine on smooth muscle cell morphology and vein graft preparation

Abstract

Venous injury following mechanical distension and its late sequelae were studied in a canine model. Jugular vein segments distended without and with papaverine (60 mg/100 ml) were compared with nondistended vein segments after they had been placed into the arterial circulation for 1 to 12 months. Arteriography showed no significant statistical discrepancy in luminal diameter of the three vein segments. Complete reendothelialization had occurred in all vein grafts at the time of harvesting. Similar histocytologic features existed in the nondistended segments and in the portion distended with human plasma protein fraction (Plasmanate) plus papaverine (150 to 300 mm Hg). The intimal-medial hyperplasia was characterized by an increase in fibrocellular layers with an elaboration of vasa vasorum. Conversely, collagen and extracellular matrix replaced the myocyte, producing medial fibrosis in vein mechanically distended with Plasmanate alone. Papaverine prevented mechanical stimulation of smooth muscle cells to overproduce extracellular connective tissue elements. Mechanical stretching of intimal and medial myocytes induced fibrogenesis and fibroplasia. Papaverine is useful in vein preparation; it protects the endothelium and smooth muscle cells in the intima and media and prevents leukocyte infiltration and medial fibrosis.

Architectonic Arrangement of the Vasa Vasorum of the Human Great Saphenous Vein

“…In particular, the role which VV play in the nutrition of the venous wall for in situ grafting during surgical treatment of obliterative disease of lower extremities was questioned, and the effects of harvesting venous grafts for aortocoronary bypassing were addressed, too [11,12,13,14,15,16,17]. …”

Exploring the Microangioarchitecture of the Vasa Vasorum of the Human Great Saphenous Vein by SEM and 3D Morphometry of Vascular Corrosion Casts

“…In the veins the vasa vasorum were studied on the human great saphenous vein (Vena saphena magna, HGSV) from the experimental as well as clinical point of view, e.g. the morphological background for the nutrition of the venous wall during the in situ grafting by the surgical treatment of the obliterative disease of lower extremities, and by harvesting the venous grafts for aorto-coronary bypassing [10][11][12][13][14][15][16]. The detailled spatial arrangement of the vasa vasorum of the HGSV was demonstrated in qualitative and quantitative terms.…”

Comparison of reversed, nonreversed translocated, and in situ vein grafts in arterial revascularization: Techniques, cumulative patency, versatility, and durability

“…Since Carrell and Guthrie used the reversed saphenous vein graft for arterial reconstruction in 1906 [1], this technique has undergone several technical modifications to earn its popularity and credibility [2][3][4]. Vein preparation has also been refined to attain optimal preservation of histocytologic integrity in order to improve graft patency [6][7][8][9][10][11][12]. Notwithstanding the periodical enthusiasm to substitute saphenous vein with biologic [13][14][15] or prosthetic grafts [16][17][18], or prosthetic graft with a venous cuff [19][20][21] for expedience, autogenous vein graft remains the preferred conduit and the gold standard in vascular bypass operations.…”

“…The anatomic orientation of reversed versus nonreversed vein graft has also been extensively evaluated for their role in long-term graft function and patency [22]. Despite the initial nongermane attitude toward vein preparation, there is evidence to support the importance of the pH, osmolality, osmolarity, and the duration of storage in media, in the preservation of the integrity of cellular and extracellular elements of the vein grafts [5,9,10,[23][24][25]. It is well established that durability and long-term patency of a vein graft is frequently the by-product of at least four vital elements: vein quality, vein preparation, anatomic orientation and surgical technique.…”