Effect of rofecoxib on colon chemical carcinogenesis at colonic anastomotic area in the rat.

AIM: To investigate the effect of the selective cyclooxygenase-2 (COX-2) inhibitor rofecoxib on the incidence of perianastomotic colonic tumors in a model of chemical carcinogenesis in the rat. EXPERIMENTAL DESIGN: Experimental study with 45 male Sprague-Dawley rats randomly assigned to one of three groups: control (n = 15) with colocolic anastomosis and chemical carcinogenesis with 1-2 dimethylhydrazine (1-2 DMH); rofecoxib 0.0027% (n = 15) with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 27 parts per million (ppm), and rofecoxib 0.0058% (n = 15) with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 58 ppm. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg of weight for 18 weeks, and colonic tumors induced were analyzed in postoperative week 20. The main parameter evaluated was the percentage of colonic neoplastic tissue, which relates tumor surface area to the colon's surface area. RESULTS: Rofecoxib at doses of 2.5 mg/kg or 0.0058 ppm significantly reduced chemical colon carcinogenesis in rats, both in the perianastomotic area and the rest of the colon (p < 0.01). In the extra-anastomotic area, rofecoxib at doses of 2.5 mg/kg has significantly greater inhibitory effect than rofecoxib in doses of 1.2 mg/kg or 0.0027 ppm (p < 0.005). CONCLUSIONS: Rofecoxib causes a reduction in chemical colon carcinogenesis in rats. This effect is sustained in the perianastomotic area, and the investigation of its role in operated colorectal cancer with risk of locoregional recurrence may therefore be of interest.

Influence of rofecoxib on experimental colonic carcinogenesis in rats.

AIM: To investigate the effect of a selective cyclooxigenase-2 (COX-2) inhibitor, rofecoxib, in the prevalence of experimental colon tumors in rats. EXPERIMENTAL DESIGN: Experimental study with 35 male Sprague-Dawley rats, divided into four groups: a) control group without experimental manipulation (n = 5); b) pharmacological carcinogenesis with 1-2 dimethylhydrazine dihydrocloride (n = 10); c) pharmacological carcinogenesis and addition of acetylsalicylic acid (AAS) (n = 10); and d) carcinogenesis and addition of rofecoxib (n = 10). Carcinogenesis was induced with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks. Colon tumors were isolated at 20 weeks. Antiinflammatory agents were given at a dose of AAS 30 mg/kg and rofecoxib at 3 mg/kg. RESULTS: The percentage of colonic tumors was significantly reduced in the rofecoxib group. This result was found for all tumors and for the malignant lesions, adenocarcinomas. CONCLUSIONS: Rofecoxib, a selective COX-2 inhibitor, reduced the percentage of drug-induced neoplastic glandular tissue in rats.

Influence of the surgical manipulation of the colon in colonic induced carcinogenesis in rats.

AIM: to investigate the influence of different experimental manipulations in a model of colonic experimental carcinogenesis with pharmacological induction in the rat. EXPERIMENTAL DESIGN: a total of 90 Sprague-Dawley male rats, divided into three groups, were used: non-surgical (n = 30); surgical with colonic trauma (n = 20), and surgical with colo-colonic anastomosis (n = 40). Carcinogenic induction was carried out with 1-2 dimethylhydrazine dihydrochloride. Colonic adenocarcinomas were identified and the number of tumors, as well as tumoral surface and percentage of tumoral surface was established. One-way ANOVA and Chi-square were employed for the statistical analysis. RESULTS: the number of tumors was greater in the surgical group than in the control group, and tumors preferentially developed around the manipulated colon. Surface and tumoral percentage were greater in the surgical group than in the control group, being also greater in the anastomosis group than in the group with colonic trauma. Within anastomosis groups, a greater tumor surface and percentage was found in the group with titanium than in the group with reabsorbable material. CONCLUSIONS: the experimental manipulation of the colon in rats enhances drug-induced colon carcingenesis. The creation of an anastomosis further increases the carcinogenic process compared with simulated anastomosis. This process is also enhanced by the quantity of suture material included in the anastomosis, and by the non-reabsorbable nature of the materials used in the anastomotic line.

Experimental model for the study of perianastomotic recurrence in colorectal cancer.

OBJECTIVE: To determine if an experimental model is valid for the study of perianastomotic recurrence in colorectal cancer, comparing it with previous experimental models. METHODS: Experimental study with 40 male Sprague-Dawley rats, assigned to one of the study groups: control group (n = 20), with manipulation of large descending bowel, and colonic anastomosis group (n = 20), with colonic section and colocolic anastomosis. After pharmacological carcinogenesis with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks, colonic tumours were studied at the 20th postoperative week. RESULTS: Number of tumours, colic tumoral area and percentage of colic tumoral area were greater in the colonic anastomosis group. In this group with colonic anastomosis all determinations were higher at the perianastomotic large bowel. CONCLUSIONS: We think this experimental model may be the best model to study perianastomotic recurrence in large bowel cancer. The high incidence of induced colic tumours and their location at the perianastomotic area offer a good field to determine response to experimental manipulations on colorrectal cancer.

La bupivacaína en el dolor postoperatorio de la herniorrafia inguinal / Bupivacaine in the management of postoperative pain associated with inguinal hernia repair

El control del dolor en el paciente operado se obtiene mediante la administración de distintos analgésicos no habiéndose modificado está conducta terapéutica en el tiempo. La anestesia local esta aceptada como parte del procedimiento de reparación de la hernia inguinal. Sin embargo, su uso para el tratamiento del dolor es una anécdota a pesar de tener una eficacia contrastada. Se revisan 68 pacientes con reparación de Shouldice a los que se practicó un bloqueo locorregional y se establecieron dos grupos dependiendo del tipo de infiltración: con suero fisiológico o con bupivacaína. Se cuantificó el dolor con una escala analógica visual a las 6 y 24 h de la intervención, estableciendo tres grupos dependiendo del nivel de dolor cuantificado y de las dosis de analgesia precisadas en las primeras 48 h. Se concluye que la infiltración con bupivacaína puede ser rutinaria en el tratamiento del dolor postoperatorio de la herniorrafia inguinal (AU)

[Abdominal cystic lymphangioma]. / Linfangioma quístico abdominal.

The cystic lymphangioma is a benign slow-growing tumor derived of the lymphatic vessels. It is presented with more frequency in the childhood and the great majority are diagnosed under 5 years of life. The most frequent localization is in head and neck, although they can be developed in any organ or soft tissue. The intraabdominal presentation is not very frequent (2-8%). The clinical presentation is very variable being the most frequent sign the appearance of an effect mass. The diagnosis of suspicion is radiological by means of abdominal ultrasonography and computed tomography. The treatment is surgical. The definitive diagnosis is always histologic. They can recidive. We present two abdominal cases that illustrate this pathology type.