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Biomedical subjects

Maria Mercedes Binda

Publications and source records attributed to Maria Mercedes Binda.

6 recordsLinked to original sources
PubMed2006

Effect of desiccation and temperature during laparoscopy on adhesion formation in mice.

OBJECTIVE: To investigate the effects of desiccation (without cooling) and of oversaturation of the pneumoperitoneum on adhesion formation. DESIGN: Prospective randomized trial. SETTING: Academic research center. ANIMAL(S): BALB/c and NMRI female mice. INTERVENTION(S): The effect of desiccation using nonhumidified CO(2) on adhesion formation was evaluated in a laparoscopic mouse model. Body temperature (BT) was maintained at 37 degrees C using a homeothermic blanket. In addition to controls without desiccation, the effect of both hypothermia and desiccation on adhesion formation was evaluated. Subsequently the effect of oversaturating the pneumoperitoneum using a high energy gas to avoid any desiccation was studied. MAIN OUTCOME MEASURE(S): During surgery BT, pneumoperitoneum temperature, and relative humidity were monitored. Adhesions were scored after 7 days. RESULT(S): Adhesions increased with increasing levels of desiccation when BT was kept at 37 degrees C. This was prevented with humidified gas. If BT decreased, adhesions were fewer. Oversaturating the pneumoperitoneum increased adhesions due to high energy gas causing an increase in both BT and pneumoperitoneum temperature. CONCLUSION(S): Adhesions increase with desiccation and decrease when BT is reduced. Adhesions are minimized when humidified gas is used. Since desiccation is associated with cooling, its effect is generally underestimated because of the counterbalance with cooling. The concept of combining controlled intraperitoneal cooling with a rigorous prevention of desiccation might be important for clinical adhesion prevention.

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PubMed2005

Adhesion formation and interanimal variability in a laparoscopic mouse model varies with strains.

Adhesion formation after laparoscopic surgery was evaluated in mice of different strains. More adhesions were observed in Swiss, NMRI, and BALB/c mice, with less interanimal variability in BALB/c mice. These data point to genetics effects on adhesion formation, which open new insights in its pathogenesis and indicate the importance of a careful strain selection for animal studies.

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PubMed2004

Effect of adding more than 3% oxygen to carbon dioxide pneumoperitoneum on adhesion formation in a laparoscopic mouse model.

OBJECTIVE: To investigate the effect of the addition of 3% or higher oxygen concentrations to the carbon dioxide (CO2) pneumoperitoneum. DESIGN: Prospective, randomized trial. SETTING: Academic research center. ANIMAL(S): Female Naval Medical Research Institute mice (n = 100). INTERVENTION(S): Sixty minutes of CO2 pneumoperitoneum with 0%, 3%, 6%, 9%, or 12% oxygen; induction of adhesions by the creation of standardized peritoneal lesions during laparoscopy. MAIN OUTCOME MEASURE(S): Adhesions were quantitatively and qualitatively scored after 7 days during laparotomy to determine [1] the effect of 60 minutes of CO2 pneumoperitoneum with 0%, 3%, 6%, 9%, or 12% oxygen on adhesion formation, and [2] the effect of duration of CO2 pneumoperitoneum and insufflation pressure on adhesion formation with the addition of 0%, 3%, and 12% oxygen. RESULT(S): Compared with a CO2 pneumoperitoneum with 3% oxygen, adhesion formation is greater when either no oxygen or more than 3% oxygen is added to the CO2 pneumoperitoneum. These effects persisted at higher insufflation pressures and longer duration of pneumoperitoneum, both known to increase adhesion formation with pure CO2. CONCLUSION(S): This study confirms that adhesion formation is decreased with the addition of 3% oxygen to the CO2 pneumoperitoneum. The addition of higher oxygen concentrations, however, is deleterious. Adhesions always increase with time and duration of the pneumoperitoneum.

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PubMed2004

The rabbit nephrectomy model for training in laparoscopic surgery.

BACKGROUND: Laparoscopic surgical training is generally done with the teacher-student model using complex exercises. This study was performed to evaluate a new training model that emphasizes the repetition of simple procedures. METHODS: Laparoscopic surgery was performed in rabbits (n=200) using conventional instruments. Gynaecologists (n=10) and medical students (n=10) performed a series of exercises during 20 full days training. Nephrectomy was chosen to evaluate and score laparoscopic skills, i.e. duration of surgery and complication rate, since it mimics the surgical challenge and involves dissection of major vessels. Each surgeon performed 20 nephrectomies, alternating left and right sides. RESULTS: Duration of surgery and complications decreased with training. For duration of surgery, a two-phase exponential decay learning curve, with different decays for gynaecologists and students, was observed. Gynaecologists achieved shorter operating times than students for real and calculated times in the first procedure (P<0.0001 and P<0.0001) and for calculated time in the last procedure (P=0.001). Severe complications were more frequent in students than in gynaecologists (P=0.0003). CONCLUSION: The rabbit nephrectomy model is suitable for training in laparoscopic surgery. Since it implies the repetition of short and well-defined exercises, progression is easier to monitor and the necessity for continuous supervision is less, making training less expensive.

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PubMed2003

Role of hypoxia inducible factors 1alpha and 2alpha in basal adhesion formation and in carbon dioxide pneumoperitoneum-enhanced adhesion formation after laparoscopic surgery in transgenic mice.

OBJECTIVE: To evaluate the role of hypoxia inducible factors (HIFs) 1alpha and 2alpha in adhesion formation after laparoscopic surgery. DESIGN: Prospective, randomized study. SETTING: Academic research center. ANIMAL(S): Forty Swiss/129SvJ wild-type mice and transgenic mice partially deficient for the genes encoding for HIF-1alpha (HIF-1alpha(+/-)) or HIF-2alpha (HIF-2alpha(+/-)). INTERVENTION(S): Adhesions were induced by standardized lesions during laparoscopy. To evaluate "basal adhesions" and "pneumoperitoneum-enhanced adhesions," the pneumoperitoneum was maintained for a minimum (10 minutes) or prolonged (60 minutes) period, respectively. MAIN OUTCOME MEASURE(S): Adhesions were blindly scored after 7 days. RESULT(S): In both HIF-1alpha and HIF-2alpha wild-type mice, pneumoperitoneum enhanced adhesion formation. In comparison with wild-type mice, basal adhesions were lower in HIF-1alpha(+/-) and similar in HIF-2alpha(+/-) mice. Pneumoperitoneum did not enhance adhesion formation in HIF-1alpha(+/-) or in HIF-2alpha(+/-) mice. Therefore, in comparison with the correspondent wild-type mice, pneumoperitoneum-enhanced adhesions were lower in HIF-1alpha(+/-) and HIF-2alpha(+/-) mice. CONCLUSION(S): These data confirm that CO(2) pneumoperitoneum enhances adhesion formation and indicate that this effect is mediated, at least in part, by an up-regulation of HIF-1alpha and HIF-2alpha.

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