INTRODUCTION: Surgical options for vascular reconstruction in a contaminated field are limited and include prosthetic reconstruction or ligation with extra-anatomic bypass. With prosthetic insertion, rates of graft infection and failures (pseudoaneurysms and thrombosis) are high. In the emergent situations, extra-anatomic bypass is time-consuming and complex, and it produces marginal long-term results. Small intestinal submucosa (SIS) is a cell-free collagen matrix derived from porcine small intestine. Preliminary studies have demonstrated its ability to be remodeled into host tissue. In this study, we compared SIS to polytetrafluoroethylene (PTFE) as a vascular patch for arterial repair in the presence of massive gastrointestinal contamination to evaluate graft patency, incorporation, infection, and aneurysm formation. METHODS: Adult mongrel pigs underwent general anesthesia with Isoflurane and were then randomized to 1 of 3 groups: control, contamination (colon puncture with stool contamination of the pelvis), or shock + contamination (40% blood volume for 1 hour, then resuscitation with shed blood and crystalloid, plus contamination). All groups then underwent a left common iliac arteriotomy and further randomized to a 1 x 3-cm patch angioplasty with either SIS or PTFE. All received cefotetan for 24 hours. All animals were sacrificed between 2 and 4 weeks, and necropsy was performed. Grafts were cultured, and microscopic analysis with hematoxylin and eosin and trichrome was performed. Outcomes included pulse quality (normal or diminished) compared with opposite side, graft infection, and pseudoaneurysm; all were determined by a blinded investigator. RESULTS: Forty animals were randomized, and 1 died of abdominal sepsis. All control animals had normal distal pulses, no pseudoaneurysms, and no patch infections. The pseudoaneurysm rate for the contaminated PTFE patches was 25% compared with 0% in the SIS group (P = 0.09). Patch infection occurred in 73% of all PTFE patches compared with 8% of SIS patches (P < 0.03). Organisms present in the infected grafts included Escherichia coli, Bacteroides species, and other Gram-negative enterics. Histopathology demonstrated the presence of neointima in both SIS and PTFE. Only SIS was completely incorporated, with infiltration of collagen fibrils and lymphocytes. CONCLUSIONS: SIS was associated with improved graft patency, less infection, complete incorporation, and no false aneurysm formation when compared with PTFE. This may be due to its ability to provide a durable scaffold for cellularization and tissue remodeling. This material may offer a superior alternative to more complex vascular reconstruction techniques in contaminated fields.
INTRODUCTION: Surgical options for vascular reconstruction in a contaminated field are limited and include prosthetic reconstruction or ligation with extra-anatomic bypass. With prosthetic insertion, rates of graft infection and failures (pseudoaneurysms and thrombosis) are high. In the emergent situations, extra-anatomic bypass is time-consuming and complex, and it produces marginal long-term results. Small intestinal submucosa (SIS) is a cell-free collagen matrix derived from porcine small intestine. Preliminary studies have demonstrated its ability to be remodeled into host tissue. In this study, we compared SIS to polytetrafluoroethylene (PTFE) as a vascular patch for arterial repair in the presence of massive gastrointestinal contamination to evaluate graft patency, incorporation, infection, and aneurysm formation. METHODS: Adult mongrel pigs underwent general anesthesia with Isoflurane and were then randomized to 1 of 3 groups: control, contamination (colon puncture with stool contamination of the pelvis), or shock + contamination (40% blood volume for 1 hour, then resuscitation with shed blood and crystalloid, plus contamination). All groups then underwent a left common iliac arteriotomy and further randomized to a 1 x 3-cm patch angioplasty with either SIS or PTFE. All received cefotetan for 24 hours. All animals were sacrificed between 2 and 4 weeks, and necropsy was performed. Grafts were cultured, and microscopic analysis with hematoxylin and eosin and trichrome was performed. Outcomes included pulse quality (normal or diminished) compared with opposite side, graft infection, and pseudoaneurysm; all were determined by a blinded investigator. RESULTS: Forty animals were randomized, and 1 died of abdominal sepsis. All control animals had normal distal pulses, no pseudoaneurysms, and no patch infections. The pseudoaneurysm rate for the contaminated PTFE patches was 25% compared with 0% in the SIS group (P = 0.09). Patch infection occurred in 73% of all PTFE patches compared with 8% of SIS patches (P < 0.03). Organisms present in the infected grafts included Escherichia coli, Bacteroides species, and other Gram-negative enterics. Histopathology demonstrated the presence of neointima in both SIS and PTFE. Only SIS was completely incorporated, with infiltration of collagen fibrils and lymphocytes. CONCLUSIONS: SIS was associated with improved graft patency, less infection, complete incorporation, and no false aneurysm formation when compared with PTFE. This may be due to its ability to provide a durable scaffold for cellularization and tissue remodeling. This material may offer a superior alternative to more complex vascular reconstruction techniques in contaminated fields.
Authors: Sandip Sarkar; Thomas Schmitz-Rixen; George Hamilton; Alexander M Seifalian Journal: Med Biol Eng Comput Date: 2007-03-06 Impact factor: 2.602
Authors: Allison J Beattie; Thomas W Gilbert; Juan Pablo Guyot; Adolph J Yates; Stephen F Badylak Journal: Tissue Eng Part A Date: 2009-05 Impact factor: 3.845