Testing of a new prototype surgical stapler that automates the rollover sleeve technique for venous anastomoses

The creation of successful vascular anastomoses is of primary importance in many surgical fields. Numerous attempts to automate this process have been made. These techniques have slowly gained acceptance, but their use is still limited. This report details feasibility testing of a new prototype stapler that automates the rollover sleeve technique for venous vascular anastomoses. Male and female mongrel dogs (n=7) (25-32 kg) were used. A segment of the right (n=5) or left (n=2) iliac vein was harvested for interposition grafts after the contra lateral side was transected. In each dog, two end-to-end venous anastomoses at the interposition grafts were performed. The standard anastomosis employed continuous mattress sutures. The experimental anastomosis was performed with a new prototype surgical stapler. The stapled anastomosis was proximal and the sutured was distal. In all experiments, it was possible to perform the experimental anastomosis with the stapler. Complications included two small leaks, one due to misfiring of a single pin in one experimental site. These leaks required suture reinforcement. One dog died of hemorrhage due to a slipped suture at the vein harvest site. One vein had thrombus seen at the sutured site although no technical abnormalities at either of the anastomoses could be found. After two weeks, grafts were inspected grossly and histologically. Healing appeared normal. There was a trend for less inflammatory cells infiltrating stapled sites; however, this was not statistically significant. The experiments demonstrate that this device can automate the rollover sleeve technique for venous anastomoses.

Factors affecting hemodynamic changes after reperfusion in liver transplantation

Background: The aim this retrospective study was to determine if the duration of cold ans warm ischemia times is related to the extent of these disturbances and also to identify other factores related to recipient's condition which may affect the severity of post reperfusion syndrome. Patients and methods: The authors studied the factors affecting hemodynamic changes after reperfusion in sixty-one patients submitted to liver transplantation at the University of Miami (Jackson Memorial Hospital) during the investigation period (August 1998-january 1999). The hemodynamic parameters monitored were heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary arterial pressure (MPAP), venous oxygen saturation (SVO2) and ASA status. All parameters were evaluted in three specific times: after skin incision (baseline, T1), 10 min. before reperfusion (T2), and 10 min. after reperfusion (T3). The statistical analyses were t-test for independent samples and ANOVA test. Results: All parameters changed significantly (p<0.0001) at T1 T2 and T3. No correlation was found between cold warm ischemia times and any of hemodynamic in our study and no correlation was found between gender and those parameters . Age was significantly correlated with the MAP at T2. MAP was decreased in older patients at T2. HR, MAP, CVP, PAP and CVO2 were significantly correlated with ASA classification (p<0,000033). Conclusions: No significant effects of cold and warm ischemia times on the hemodynamic intraoperative condition of the ILT were found. Furthermore, patients with a high ASA status were shown to b e at an increased risk of cardiovascular collapse after reperfusion

Graft versus host disease in a rat small bowel transplant model after T-cell depleted donor specific bone marrow infusion

Low cytoreductive regimen of irradiation associated to unmodified bone marrow infusion (UBM) does not prevent the occurrence of graft versus host disease (GVHD) after transplant. PURPOSE: In this study we evaluated the potential advantages of a long-term immunossupression and T-cell depleted bone marrow infusion (TCDBMI) in preventing the occurrence of GVHD after small bowel transplantation (SBTx). METHODS: Heterotopic SBTX was performed with Lewis rats as recipients and DA as donors and distributed into 5 groups according to the irradiation, duration of immunossupression and the use of UBM or TCDBMI: G1 (n=6), without irradiation and G2 (n=9), G3 (n=4), G4 (n=5) and G5 (n=6) was given 250 rd of irradiation. Groups 1,2,4 and G3 and 5 were infused with 100 x 106 UBM and TCDBM respectively. Animals in G1, 2, 3 were immunossupressed with 1mg/ FK506/Kg/IM for 5 days and G4 and G5 for 15 days. Anti CD3 monoclonal antibodies and immunomagnetic beads were used for T-cell depletion.Animals were examined for rejection, GVHD, chimerism characterization and ileal and skin biopsies. RESULTS: Minimal to mild rejection was observed in all groups; however, GVHD were present only in irradiated groups. Long-term immunossupression changed the severity of GVHD in G4 and G5. Rejection was the cause of death in G1 while GVHD in G2, 3, 4 and 5, not avoided by the use of TCDBMI. Total chimerism and T-cell chimerism was statistically higher in irradiated groups when compared to G1. CONCLUSION: Extended immunossupression associated to low dose of irradiation decrease the severity of GVHD, not avoided by the use of TCDBMI.