Absorbable suture improves growth of venous anastomoses A. M a r c Gillinov, M D , A n t h o n y W. Lee, BSE, J o h n M. R e d m o n d , M D , K e n t o n J. Zehr, M D , Louis Jackson, Elizabeth A. Davis, BA, R a l p h H . H r u b a n , M D , G. Melville Williams, M D , and D u k e E. C a m e r o n , MD, Baltimore, Md. Growth of vascular anastomoses is desirable in pediatric vascular surgery, especially in pediatric organ transplantation. Although absorbable suture has been shown to be superior to nonabsorbable suture in permitting growth of arterial anastomoses, the optimal suture material for venous anastomoses has not been established. To examine this in a porcine model, we performed bilateral primary end-to-end anastomoses of transected external jugular veins in 10, 4-week-old piglets. In each piglet one anastomosis was constructed with continuous absorbable 8-0 polyglyconate suture, whereas the contralateral anastomosis was constructed with continuous nonabsorbable 8-0 polypropylene suture. After 6 months the veins were excised, pressure fixed at 15 mm Hg for 2 hours, and examined grossly and histologically. Vein diameter was measured by contrast radiography at the anastomosis and 1 cm proximal and distal to the anastomosis. Vein cross-sectional area 1 cm from the anastomosis was similar in the two groups: polyglyconate 95.7 + 12.3 mm 2 versus polypropylene 95.3 + 9.7 mm 2. However, polyglyconate anastomoses had greater cross-sectional area (polyglyconate 72.8 + 7.9 mm 2vs polypropylene 51.8 + 6.0 mm2;p < 0.05). In addition, at 6 months polyglyconate anastomoses had a greater percentage of growth (polyglyconate 207% vs polypropylene 118%;p < 0.05) compared with native vein cross-sectional area (23.7 -+ 0.39 mm 2) from control pigs at 4 weeks of age. On histologic examination, polyglyconate had dissolved entirely in six cases and was present but in varying degrees of dissolution in the other four; in contrast, polypropylene was identifiable at all anastomoses. These results suggest that absorbable suture is superior to nonabsorbable suture for construction of venous anastomoses when anastomotic growth is important. (J VASC SURG 1992;769-73.)
In organ transplantation the fate o f the graft depends on the patency o f vascular anastomoses. This is particularly important in pediatric transplantation, in which the anastomosis must not only remain patent but grow. Several clinical studies have demonstrated that posrtransplant anastomotic stenosis occurs more frequently in children than in adults.la Use o f sutures and techniques that maximize growth is therefore o f paramount importance in such pediatric vascular anastomoses. Previous studies have examined the influence o f suture type (absorbable vs nonabsorbable) on anastomotic growth in arteries, and it is clear that greater growth is achieved when From the Departments of Cardiac Surgery,Vascular Surgery,and Pathology, the Johns Hopkins Hospital, Baltimore. Supported by Davis and Geck, American Cyanamid Company, Wayne, N.J. Presented at the Fourth AnnualMeeting of the AmericanVenous Forum, Coronado, Calif., Feb. 26-28, 1992. Reprint requests: Duke E. Cameron,MD, Department of Cardiac Surgery, the Johns Hopkins Hospital, Blalock Bldg., Room 618, 600 N. Wolfe St., Baltimore,MD 21205. 24/1/40410
absorbable sutures are employed. 47 However, the optimal suture material for venous anastomoses in the growing patient has not been established. Monofilament absorbable sutures might afford growth benefit in venous anastomoses. In this study we compared the growth potential o f monofilament polyglyconate (Maxon; Davis and Geck, Danbury, Conn.) and polypropylene (Prolene; Ethicon, Somerville, N.J.) suture in the construction o f end-to-end anastomoses o f the external jugular vein in the growing piglet. METHODS Ten 4-week-old piglets (weight 8.8 + 2.5 kg, mean + SD) were premedicated with ketamine (10 mg/kg intramuscularly) and anesthetized with pentobarbitol (200 mg/kg intravenously). Piglets were intubated endotracheally and placed on a Harvard volume-cycled ventilator (Harvard Apparatus Co., Inc., S. Natick, Mass.). Each animal received penicillin G (500 m g intravenously) before skin incision. External jugular veins on both sides were exposed and 769
770
jo~nal of VASCULAR SURGERY
Gillinov et al.
t20
300 -
q100
E 80 ¸
0
60]
0
40-
200
m
Potyglyconate Polypropylene
c-
O
L~
o
100
20
Juxta-Anastornotic
Vein
Anastomosis
Vessel Site Fig. 1. Cross-sectional area o f veins at anastomoses a n d 1 c m f r o m anastomoses (juxtaanastomotic vein) for anastomoses constructed with polyglyconate and polypropyl-
ene (*p < 0.05). dissected free of surrounding subcutaneous tissue for a distance of 6 cm. Care was taken not to disrupt the adventitia, and veins were kept moist with saline solution containing papaverine (60 mg/dl). Branches were ligated with 5-0 silk suture. After dissection was complete, the animals received heparin (100 mg/kg intravenously), and vascular clamps were applied proximally and distally. Veins were divided at their midpoints and end-to-end anastomoses were performed with continuous 8-0 suture. In each animal, one anastomosis was constructed with polyglyconate suture and the contralateral anastomosis with polypropylenc suture. All anastomoses were performed by the same surgeon with the aid of 2.5 power magnification surgical loupes. An external 7-0 polypropylene suture was used to mark the site of each anastomosis. Animals were cared for in cages until the skin wounds healed. They were then transferred to free-range pens, where they remained for 6 months. On return to the laboratory, animals were anesthetized as above. Each external jugular vein was dissected free along its entire length. During dissection, veins were kept moist with a dilute nitroglyc-
Polyglyconate
Potypropylene
Suture Fig. 2. Percent growth of anastomoses. Cross-sectional areas were compared with native external jugular vein from 4-week-old piglets (*p < 0.05). erine solution (0.05 mg/ml). Veins were removed and placed in nitroglycerin solution for 60 minutes to minimize vascular spasm. Each vein was pressure fixed with formalincontaining contrast medium at 15 mm H g for 2 hours. Radiographs were taken, and vein diameter was measured 1 cm proximal and 1 cm distal to the anastomosis and at the anastomosis itself. All measurements were made by two observers without knowledge of the suture material used. The veins were then opened longitudinally, fixed in formalin, and embedded in paraffm. Five-micron sections were stained with hematoxylin and eosin. In two additional 4-week-old piglets, external jugular veins were excised and diameters were measured by contrast radiography as described above. Venous cross-sectional areas were determined and served as control values. After surgical procedures were completed, fiflly anesthetized animals were killed by exsanguination.
Volume 16 Number 5 November 1992
Absorbable suture and venous anastomoses 771
Throughout the study, animal care complied with the Principles of Laboratory Animal Care (formulated by the National Society for Medical Research) and the Guide for the Care and Use of Laboratory Animals (National Institutes of Health publication No. 8023, revised 1985). All values are expressed as mean + SEM unless otherwise noted. Statistical significance of differences between the two groups was evaluated by a twotailed unpaired t test. A p value _
In organ transplantation the fate o f the graft depends on the patency o f vascular anastomoses. This is particularly important in pediatric transplantation, in which the anastomosis must not only remain patent but grow. Several clinical studies have demonstrated that posrtransplant anastomotic stenosis occurs more frequently in children than in adults.la Use o f sutures and techniques that maximize growth is therefore o f paramount importance in such pediatric vascular anastomoses. Previous studies have examined the influence o f suture type (absorbable vs nonabsorbable) on anastomotic growth in arteries, and it is clear that greater growth is achieved when From the Departments of Cardiac Surgery,Vascular Surgery,and Pathology, the Johns Hopkins Hospital, Baltimore. Supported by Davis and Geck, American Cyanamid Company, Wayne, N.J. Presented at the Fourth AnnualMeeting of the AmericanVenous Forum, Coronado, Calif., Feb. 26-28, 1992. Reprint requests: Duke E. Cameron,MD, Department of Cardiac Surgery, the Johns Hopkins Hospital, Blalock Bldg., Room 618, 600 N. Wolfe St., Baltimore,MD 21205. 24/1/40410
absorbable sutures are employed. 47 However, the optimal suture material for venous anastomoses in the growing patient has not been established. Monofilament absorbable sutures might afford growth benefit in venous anastomoses. In this study we compared the growth potential o f monofilament polyglyconate (Maxon; Davis and Geck, Danbury, Conn.) and polypropylene (Prolene; Ethicon, Somerville, N.J.) suture in the construction o f end-to-end anastomoses o f the external jugular vein in the growing piglet. METHODS Ten 4-week-old piglets (weight 8.8 + 2.5 kg, mean + SD) were premedicated with ketamine (10 mg/kg intramuscularly) and anesthetized with pentobarbitol (200 mg/kg intravenously). Piglets were intubated endotracheally and placed on a Harvard volume-cycled ventilator (Harvard Apparatus Co., Inc., S. Natick, Mass.). Each animal received penicillin G (500 m g intravenously) before skin incision. External jugular veins on both sides were exposed and 769
770
jo~nal of VASCULAR SURGERY
Gillinov et al.
t20
300 -
q100
E 80 ¸
0
60]
0
40-
200
m
Potyglyconate Polypropylene
c-
O
L~
o
100
20
Juxta-Anastornotic
Vein
Anastomosis
Vessel Site Fig. 1. Cross-sectional area o f veins at anastomoses a n d 1 c m f r o m anastomoses (juxtaanastomotic vein) for anastomoses constructed with polyglyconate and polypropyl-
ene (*p < 0.05). dissected free of surrounding subcutaneous tissue for a distance of 6 cm. Care was taken not to disrupt the adventitia, and veins were kept moist with saline solution containing papaverine (60 mg/dl). Branches were ligated with 5-0 silk suture. After dissection was complete, the animals received heparin (100 mg/kg intravenously), and vascular clamps were applied proximally and distally. Veins were divided at their midpoints and end-to-end anastomoses were performed with continuous 8-0 suture. In each animal, one anastomosis was constructed with polyglyconate suture and the contralateral anastomosis with polypropylenc suture. All anastomoses were performed by the same surgeon with the aid of 2.5 power magnification surgical loupes. An external 7-0 polypropylene suture was used to mark the site of each anastomosis. Animals were cared for in cages until the skin wounds healed. They were then transferred to free-range pens, where they remained for 6 months. On return to the laboratory, animals were anesthetized as above. Each external jugular vein was dissected free along its entire length. During dissection, veins were kept moist with a dilute nitroglyc-
Polyglyconate
Potypropylene
Suture Fig. 2. Percent growth of anastomoses. Cross-sectional areas were compared with native external jugular vein from 4-week-old piglets (*p < 0.05). erine solution (0.05 mg/ml). Veins were removed and placed in nitroglycerin solution for 60 minutes to minimize vascular spasm. Each vein was pressure fixed with formalincontaining contrast medium at 15 mm H g for 2 hours. Radiographs were taken, and vein diameter was measured 1 cm proximal and 1 cm distal to the anastomosis and at the anastomosis itself. All measurements were made by two observers without knowledge of the suture material used. The veins were then opened longitudinally, fixed in formalin, and embedded in paraffm. Five-micron sections were stained with hematoxylin and eosin. In two additional 4-week-old piglets, external jugular veins were excised and diameters were measured by contrast radiography as described above. Venous cross-sectional areas were determined and served as control values. After surgical procedures were completed, fiflly anesthetized animals were killed by exsanguination.
Volume 16 Number 5 November 1992
Absorbable suture and venous anastomoses 771
Throughout the study, animal care complied with the Principles of Laboratory Animal Care (formulated by the National Society for Medical Research) and the Guide for the Care and Use of Laboratory Animals (National Institutes of Health publication No. 8023, revised 1985). All values are expressed as mean + SEM unless otherwise noted. Statistical significance of differences between the two groups was evaluated by a twotailed unpaired t test. A p value _
