Occlusive vascular stapling in a canine inferior vena cava model D. Kevin Lurie, MD, 1 Douglas Webster, DO, 2 Michael Lutz, MD, 3 Jennifer Engle, BS, 4 and John Shaldenbrand, MD, ~ Detroit, Mich. A canine m o d e l for inferior vena cava resection was devised to study the biomechanical and clinical applications o f the cartridge stapler, which applies a triple staggered staple line. Eighteen m o n g r e l dogs were subjected to subhepatic, suprarenal inferior vena cava occlusion with excision o f the excluded segment. A t I hour, six dogs were killed and inferior vena cava sizes and pressures were measured. All staple lines were intact. The inferior vena cava bursting pressure was 150 to 300 m m H g . Ten dogs survived to 6 weeks and u n d e r w e n t repeat l a p a r o t o m y with excision and measurement o f the r e m a i n i n g inferior vena cava. M e a n diameter was 1.9 cm. N o evidence o f staple line leakage was f o u n d despite chronic pressures to 39 cm H 2 0 : median static bursting pressures were 250 m m H g . Vein wall thickness o f > 0 . 2 4 m m were all satisfactorily stapled. Histologic examination revealed n o r m a l reendothelialization, with i m p r o v e d healing at higher chronic pressures. N o evidence o f inflammation at the staple line o r foreign b o d y reaction was found. W e conclude that a triple staple line provides secure, r a p i d venous occlusion that can w i t h s t a n d supraphysiologic stresses immediately and at 6 weeks. (J VASC SURG 1990;12:38-40.)
Since the introduction and adoption of automatic stapling instruments in the United States in the late 1950s and early 1960s many investigators have reported on the clinical applications for these tools in thoracic and general surgery. Surprisingly, the linear •vascular type of stapler has not generated a shnilar interest. Little data are available on the vascular stapler, and guidelines for its use have not been tested. Its suggested use is on vessels 1 to 2.5 rnm in wall thickness, making the pulmonary vessels and systemic veins best-suited vessels? Accordingly, a canine model for inferior vena cava (IVC) resection has been devised to test the occlusive integrity of the TA-30:Va stapler (U.S. Surgical Corp., Norwalk, Conn.), on different sized veins to clarify its efficacy. The TA-30:V3 is a modified TA-30 cartridge stapler often used in gastrointestinal surgery. The staple From the Departments of Surgery, ~'2'4Urology,s mad Pathology, 5 Sinai Hospital of Detroit. Dr. Lurie is currently at the Kaiser Foundation Health Plan of the MidAtlantic States, Inc., Washington, DC. Dr. Webster is currently at the Chicago College of Osteopathy. Dr. Engle is currently at Wayne State University School of Medicine, Detroit. Dr. Shaldenbrand is currently at St. Joseph's Hospital, Ann Arbor, Mich. Presented in part at the Eigtaty-third annual meeting of the American Urological Association, Boston, Mass., June 3-7, 1988, and published ha abstract form J Uro11988;139(4,pt.2):210A. Reprint requests: D. Kevin Lurie, MD, Kaiser Foundation Health Plan of the Mid-AtlanticStates, Inc., 4200 Wisconsin Ave. NW, Suite 300, Washington, DC 20016. 24/1/19124 38
cartridge contains 23 staples released in a triple staggered array. METHODS The study protocol was approved by the Sinai Hospital of Detroit Animal Research Committee. Eighteen mongrel dogs (15 to 50 kg) were anesthetized with intravenous pentobarbital (50 mg/kg) and subjected to midline laparotomy. The IVC was dissected free of the retroperitoneum from the renal veins to the hepatic veins and looped with ves~o~/ loops. The IVC diameter was measured, and continuous IVC pressure was measured with a transducer. The linear stapler was then applied above the renal~ veins, below the hepatic veins, and a third staple line was placed in the midposition. The excluded IVC segment, with the middle row of staples intact, was excised and fixed in formalin for later histologic examination (Fig. 1). A dry pack was placed on the distal IVC for 60 seconds. Continued bleeding at'this point was considered inadequate hemostasis. The laparotomy was then closed. To measure short-term staple line integrity, six dogs (defined as the acute group) were killed 1 hour after staple occlusion of the IVC. Pressures in the IVC were measured, and bursting pressure was de-' termined. These vessels were then fixed and were later measured by means of ocular micrometry. The remaining 12 dogs were killed at 6 weeks, and all of the staple lines were removed and examin~
Since the introduction and adoption of automatic stapling instruments in the United States in the late 1950s and early 1960s many investigators have reported on the clinical applications for these tools in thoracic and general surgery. Surprisingly, the linear •vascular type of stapler has not generated a shnilar interest. Little data are available on the vascular stapler, and guidelines for its use have not been tested. Its suggested use is on vessels 1 to 2.5 rnm in wall thickness, making the pulmonary vessels and systemic veins best-suited vessels? Accordingly, a canine model for inferior vena cava (IVC) resection has been devised to test the occlusive integrity of the TA-30:Va stapler (U.S. Surgical Corp., Norwalk, Conn.), on different sized veins to clarify its efficacy. The TA-30:V3 is a modified TA-30 cartridge stapler often used in gastrointestinal surgery. The staple From the Departments of Surgery, ~'2'4Urology,s mad Pathology, 5 Sinai Hospital of Detroit. Dr. Lurie is currently at the Kaiser Foundation Health Plan of the MidAtlantic States, Inc., Washington, DC. Dr. Webster is currently at the Chicago College of Osteopathy. Dr. Engle is currently at Wayne State University School of Medicine, Detroit. Dr. Shaldenbrand is currently at St. Joseph's Hospital, Ann Arbor, Mich. Presented in part at the Eigtaty-third annual meeting of the American Urological Association, Boston, Mass., June 3-7, 1988, and published ha abstract form J Uro11988;139(4,pt.2):210A. Reprint requests: D. Kevin Lurie, MD, Kaiser Foundation Health Plan of the Mid-AtlanticStates, Inc., 4200 Wisconsin Ave. NW, Suite 300, Washington, DC 20016. 24/1/19124 38
cartridge contains 23 staples released in a triple staggered array. METHODS The study protocol was approved by the Sinai Hospital of Detroit Animal Research Committee. Eighteen mongrel dogs (15 to 50 kg) were anesthetized with intravenous pentobarbital (50 mg/kg) and subjected to midline laparotomy. The IVC was dissected free of the retroperitoneum from the renal veins to the hepatic veins and looped with ves~o~/ loops. The IVC diameter was measured, and continuous IVC pressure was measured with a transducer. The linear stapler was then applied above the renal~ veins, below the hepatic veins, and a third staple line was placed in the midposition. The excluded IVC segment, with the middle row of staples intact, was excised and fixed in formalin for later histologic examination (Fig. 1). A dry pack was placed on the distal IVC for 60 seconds. Continued bleeding at'this point was considered inadequate hemostasis. The laparotomy was then closed. To measure short-term staple line integrity, six dogs (defined as the acute group) were killed 1 hour after staple occlusion of the IVC. Pressures in the IVC were measured, and bursting pressure was de-' termined. These vessels were then fixed and were later measured by means of ocular micrometry. The remaining 12 dogs were killed at 6 weeks, and all of the staple lines were removed and examin~
