Disparities on prostate cancer survival in Mexico: a retrospective cohort study.

OBJECTIVE: To estimate prostate cancer (PC) survival in Mexico and explore survival disparities according to the marginalization level of residence place. MATERIALS AND METHODS: A nationwide administrative claims database (4 110 men) whose PC treatment was financed by Seguro Popular between 2012-2016, was cross-linked to the National Mortality Registry up to December 2019. Patients were classified according to their oncological risk at diagnosis and the marginalization level of the residence municipality. Cox proportional hazards regression was used to estimate multivariable survival functions. RESULTS: Five-years PC survival (69%; 95%CI: 68,71%) ranged from 72% to 54% at very low and very high marginalization, respectively (p for trend<0.001). The lowest PC survival was observed in men with high-risk PC (47%; 95%CI: 33,66%) residents in very high marginalization municipalities. CONCLUSIONS: Overall, PC survival was lower than that reported in other Latin American countries. The distribution of oncologic risk and survival differences across marginalization levels suggests limited early detection and cancer health disparities.

Prostate cancer screening in low- and middle-income countries: the Mexican case.

Prostate-specific antigen (PSA)-based early detection for prostate cancer is the subject of intense debate. Implementation of organized prostate cancer screening has been challenging, in part because the PSA test is so amenable to opportunistic screening. To the extent that access to cancer screening tests increases in low- and middle-income countries (LMICs), there is an urgent need to thoughtfully evaluate existing and future cancer screening strategies to ensure benefit and control costs. We used Mexico's prostate cancer screening efforts to illustrate the challenges LMICs face. We provide five considerations for policymakers for a smarter approach and implementation of PSA-based screening.

El uso del Antígeno Prostático Específico (APE) para tamizaje para cáncer de próstata sigue siendo tema de amplio debate. La implementación de estrategias de tamiz organizado de cáncer de próstata ha sido un reto en parte porque la prueba de APE se presta para detección oportunista. A medida que aumenta el acceso a las pruebas de detección de cáncer en los países de ingresos bajos y medianos (PIBM), existe la necesidad urgente de evaluar cuidadosamente las estrategias actuales y futuras de detección oportuna de cáncer para garantizar su beneficio y controlar sus costos. Utilizamos los esfuerzos de tamizaje de cáncer de próstata de México para ilustrar los retos para PIBM. Ofrecemos cinco consideraciones dirigidas a tomadores de decisión que permitan contar con estrategias racionales de implementación de tamizaje para cáncer de próstata basado en el uso de APE.

Smoking and prostate cancer: a life course analysis.

BACKGROUND: Inconsistent associations between smoking status and prostate cancer (PC) could be due to exposure assessment error. Reconstructing smoking behaviors over the life course could reduce exposure assessment error. METHODS: As part of a case-control study, we identified 402 incident and histologically confirmed PC cases that were matched by age (±5 years) to 805 population controls. Through direct interview, we obtained information about: age at smoking onset, intensity and frequency of cigarette smoking at different life stages, and smoking cessation age. Smoking status at interview and average smoking index over the lifetime (packs/year) were estimated. Life course smoking patterns were obtained applying the k-means+ method for longitudinal data to the smoking index (pack/year) for each life stage. RESULTS: Two life-course smoking patterns were identified among ever smokers: "pattern A" characterized by males who reported low and constant smoking intensity (87.8%), and "pattern B" (12.2%) males with an initial period of low intensity, followed by an increase during the second period. Compared to never smokers, pattern B was associated with higher poorly differentiated PC, (OR 2.30; 95% CI 1.21-4.38). No association was observed with average smoking index. CONCLUSION: Life course smoking patterns seem to capture the smoking variability during life course and reduce the likelihood of reverse causation. Using this assessment strategy our findings support the potential role of tobacco smoking in PC, particularly poorly differentiated PC. Prospective studies with comprehensive smoking history during the lifetime are needed to confirm these findings.

Efficacy of Tamsulosin, Oxybutynin, and their combination in the control of double-j stent-related lower urinary tract symptoms.

INTRODUCTION AND OBJECTIVE: Indwelling double J ureteral stents are used routinely in the resolution of ureteral obstruction caused by different etiologies. Evaluation of urinary symptoms related to double-J stent, indicate that these affect 73-90% of patients. We conducted a prospective, randomized study, to evaluate the efficacy of tamsulosin, oxybutinin and combination therapy in improving the urinary symptoms. METHODS: Patients who underwent ureteral stent placement after ureterolithotripsy (total 51), were randomized into three groups: Group I: Tamsulosin 0.4 mg. Once per day(17 patients), Group II: Oxybutinin 5 mg. once per day (17 patients), Group III: Tamsulosin+ oxybutynin once per day (17 patients). All the groups received the drugs for three weeks and completed a Spanish validated Ureteral Stent Symptom Questionnaire (USSQ) at day 7 and 21. RESULTS: Repeated measures ANOVA showed mean urinary symptom index score was 22.3 vs. 15.5 in group three (p<0.001) at day 7 and 21 respectively. The mean work performance index was 6.6 vs 8.1 (p=0.049) favoring tamsulosin group, the mean sexual score was 0.5 vs 1.5 (p=0.03). Among additional problems the mean was 7.2 vs 6.2 (p=0.03). No significant difference was noted among pain and general health index. No side effects were reported. CONCLUSIONS: Combination therapy with tamsulosin and oxybutynin improved irritative symptoms and work performance as well as sexual matters. Combination therapy should be considered for patients who complained of stent related symptoms.

Advantages and Short-Term Outcomes of Laparoscopic-Assisted Renal Surgery in Elderly Patients.

OBJECTIVE: To compare the perioperative results of adult and elderly patients undergoing laparoscopic renal surgery. METHODOLOGY: Retrospective, analytical study. 448 who underwent kidney surgery for benign or malignant pathologies between 2011-2019 were included in the General Hospital of Mexico "Dr. Eduardo Liceaga". They were categorized into two groups: Group 1 <60 years and Group 2 >60 years. Descriptive statistics and bivariate analysis were performed, the calculations were performed with 95% reliability and a value of p (<0.05). RESULTS: In the group over 60 years of age, the following was found: Age: 67.1 years (60-83). IMC 28.3 kg/m2 (19-48.7). Intra and postsurgical outcomes: intraoperative bleeding = 184.4cc (5-1700). Surgical Time = 112.6min (30-240). Days of hospital stay = 2 (1-7). Complications in 2.6% (Clavien-Dindo: I = 2; II = 1), no conversion was required in any patient. There were no statistically significant differences with group 1, an exception for intraoperative bleeding. CONCLUSIONS: Our study is a pioneer in Latin America in the evaluation of the geriatric population and outcomes with laparoscopic surgery and we recommend that renal procedures with a laparoscopic approach should be considered as the best strategy in the management of benign or malignant renal pathology in geriatric patients.

[Testicular Microlithiasis: Update on diagnosis and management.] / Actualidades sobre microlitiasis testicular.

Testicular microlithiasis (TM) is an uncommonurologic condition incidentally diagnosed byscrotal ultrasound. It has been associated with differentdiseases, such as Klinefelter`s syndrome, testicular atrophy,cryptorchidism, testicular torsion, and infertility.However, it can also present in healthy males that haveno associated risk factors. Currently, TM is most oftendetected thanks to the superior resolution of today's ultrasoundequipment, compared with former models. In the1990s, TM was considered a benign condition with noimportant clinical relevance, but later reports associatedit with the development of testicular neoplasias andinfertility. Thus, many authors recommended periodic surveillance with tumor markers and ultrasound imaging,with some even promoting the use of testicular biopsy.The aim of this article is to clearly and specifically presentcurrent information about testicular microlithiasis, toestablish both diagnostic and follow-up indications.

La microlitiasis testicular (MT) es un padecimiento urológico poco frecuente que se diagnostica de forma incidental mediante ltrasonografía escrotal. Ha sido asociado a diversas enfermedades como síndrome de Klinefelter, atrofia testicular, criptorquidia, torsión testicular e infertilidad. Sin embargo, también se puede encontrar en varones sanos sin factores de riesgo asociados. La microlitiasis testicular es detectada con mayor frecuencia en la actualidad, debido a la resolución superior de los equipos de ultrasonido actuales en comparación a los anteriores.  En la década de los  noventa la MT fue considerada una condición benigna sin gran relevancia clínica. Sin embargo, reportes posteriores asociaron este padecimiento al desarrollo de neoplasias testiculares e infertilidad. Por tal motivo muchos autores recomendaban la vigilancia periódica con marcadores tumorales y ultrasonido, e incluso algunos preconizaban el uso de la biopsia testicular. El objetivo del presente articulo de revisión es exponer de manera clara y especifica la evidencia actual de la microlitiasis testicular para así establecer las pautas tanto diagnósticas como de seguimiento.

Treatment of reno-ureteral colic by twelfth intercostal nerve block with lidocaine versus intramuscular diclofenac.

INTRODUCTION AND OBJECTIVE: Renal colic is one of the most intense pains known to humans. Standard treatment usually consists of nonsteroidal anti-inflammatory drugs and opiates, but they do not always provide optimum efficacy and speed in relieving the pain. For more than 25 years, our hospital has been employing twelfth subcostal nerve block. The objective of the present study was to compare the efficacy of subcostal nerve block with lidocaine versus intramuscular diclofenac in renal colic management. METHODS: Sixty patients of both sexes, above the age of 18 years, and presenting with renal colic were randomly selected for the study. The visual analog scale was applied prior to the treatment and at minutes 1, 3, 5, 30, and 45 after the application of the twelfth nerve block or the intramuscular administration of diclofenac. RESULTS: A total of 60 patients, 35 women and 25 men, were included in the study. There were statistically significant differences in the mean scores for pain from minute 1 to minute 45. There were no adverse effects. CONCLUSIONS: Twelfth Subcostal nerve block with lidocaine is an efficacious, safe, inexpensive, and very fast-acting medication for pain control related to renal colic. These characteristics make it superior to diclofenac.

History of gonorrhea and prostate cancer in a population-based case-control study in Mexico.

UNLABELLED: We evaluated the association between a history of sexually transmitted diseases (STDs) and the risk for prostate cancer (PC) among Mexican males. METHODS: PC incident cases (n=402) that were identified at six public hospitals in Mexico City were matched by age (±5 years) with 805 population controls with no history of PC. By face-to-face interview, we obtained information about sexual history, previous STDs, sociodemographic characteristics, and familial history of PC. An unconditional logistic regression model was used to estimate the risk for PC. RESULTS: A total of 16.6% of men reported having had at least one previous STD, and the most frequently reported STD was gonorrhea (10.5%). After adjusting by PC familial history, the history of STD was associated with a two-fold greater risk of PC: odds ratio (OR)=2.67; 95% confidence interval (95% CI=1.91-3.73). When each STD was evaluated separately, only gonorrhea was associated with a significant increase in PC risk (OR=3.04; 95% CI=1.99-4.64). These associations were similar when we stratified by low-risk PC (Gleason <7) and high-risk PC (Gleason ≥7). CONCLUSION: These results confirm that STDs, and particularly gonorrhea, may play an etiological role in PC among Mexican males, which is consistent with a previous report from a multiethnic cohort.

A comparative study on the use of tamsulosin versus alfuzosin in spontaneous micturition recovery after transurethral catheter removal in patients with benign prostatic growth.

PURPOSE: To compare the efficacy and safety of tamsulosin and alfuzosin in patients with acute urinary retention (AUR) secondary to benign prostatic hyperplasia (BPH). METHODS: Ninety men with AUR due to BPH underwent urinary catheterization and were randomly assigned to treatment groups with tamsulosin 0.4 mg (37 patients), alfuzosin 10 mg (34 patients), and placebo (19 patients). After 4 days of the drug treatment, the catheters were removed, and the patients underwent trial without catheter (TWOC). A TWOC was considered successful if the patient had a voided volume >100 ml and post-void residual urine <200 ml. RESULTS: TWOC was successful in 16 patients (43.2 %) in the tamsulosin group, 12 patients (35.2 %) in the alfuzosin group, and 5 patients (26.3 %) in the placebo group. Logistic regression analysis showed that both drugs were equally effective and that the type of alpha-blocker was not a predictive factor for TWOC success (OR 1.137, 95 % CI 0.639-2.022) (p = 0.662). CONCLUSION: Even though there were no statistically significant differences when comparing the three groups, tamsulosin showed a tendency to be more effective in a successful catheter removal. The lack of objective criteria in the definition of successful micturition leads us to believe that the effectiveness of both drugs reported in the literature is overestimated.

Prostate cancer screening in low- and middle- income countries: the Mexican case / Tamizaje para cáncer de próstata en países de bajos y medianos ingresos: el caso mexicano

Abstract: Prostate-specific antigen (PSA)-based early detection for prostate cancer is the subject of intense debate. Implementation of organized prostate cancer screening has been challenging, in part because the PSA test is so amenable to opportunistic screening. To the extent that access to cancer screening tests increases in low- and middle-income countries (LMICs), there is an urgent need to thoughtfully evaluate existing and future cancer screening strategies to ensure benefit and control costs. We used Mexico's prostate cancer screening efforts to illustrate the challenges LMICs face. We provide five considerations for policymakers for a smarter approach and implementation of PSA-based screening.

Resumen : El uso del Antígeno Prostático Específico (APE) para tamizaje para cáncer de próstata sigue siendo tema de amplio debate. La implementación de estrategias de tamiz organizado de cáncer de próstata ha sido un reto en parte porque la prueba de APE se presta para detección oportunista. A medida que aumenta el acceso a las pruebas de detección de cáncer en los países de ingresos bajos y medianos (PIBM), existe la necesidad urgente de evaluar cuidadosamente las estrategias actuales y futuras de detección oportuna de cáncer para garantizar su beneficio y controlar sus costos. Utilizamos los esfuerzos de tamizaje de cáncer de próstata de México para ilustrar los retos para PIBM. Ofrecemos cinco consideracio nes dirigidas a tomadores de decisión que permitan contar con estrategias racionales de implementación de tamizaje para cáncer de próstata basado en el uso de APE.

Emphysematous pyelonephritis: multicenter clinical and therapeutic experience in Mexico.

OBJECTIVE: To analyze the outcomes of emphysematous pyelonephritis (EPN), the impact of different treatment modalities, and to determine risk factors associated with mortality. METHODS: We retrospectively reviewed cases of EPN from 3 tertiary care institutions in Mexico. The diagnosis was confirmed with computed tomographic scan. Treatment was classified as follows: medical management (MM), minimally invasive, and surgical. Demographic, clinical, biochemical, and radiological characteristics were assessed and compared between survivors and nonsurvivors. Comparison was assessed using 1-way analysis of variance and chi-square. Univariate and multivariate logistic regression analyses were performed to determine prognostic factors. Main end point was mortality. RESULTS: A total of 62 patients were included (49 women and 13 men), with a mean age of 53.9 years. The most common comorbidities were diabetes (69.3%) and hypertension (40.3%). Escherichia coli was the most common isolated microorganism (62.7%). MM was provided to 24.2%, minimally invasive treatment to 51.6%, open drainage to 19.3%, and emergency nephrectomy to 4.8%. Overall mortality was 14.5% and was similar among different treatment modalities (P=.06). Survivors were younger (P=.004), had lower creatinine (P=.002), and better estimated glomerular filtration rate (P=.007). In univariate analysis, age (P=.009), creatinine (P=.009), and need for nephrectomy (P=.03) were associated with mortality. In multivariate logistic regression analysis, creatinine (odds ratio 1.56, 95% confidence interval 1.03-2.35, P=.03) and nephrectomy (odds ratio 9.7, 95% confidence interval 1.007-93.51, P=.049) remained significant predictors of mortality. CONCLUSION: EPN needs an aggressive MM and stepwise approach; nephrectomy should be the last resort of treatment. Creatinine level and need for nephrectomy are the strongest predictors of mortality according our analysis.

Nephron-sparing surgery for clear cell carcinoma in a solitary functional kidney. Case report and literature review.

BACKGROUND: Since the introduction of nephron-sparing surgery, patients with small renal masses and diseases affecting overall renal function have greatly benefited. CLINICAL CASE: We present the case of a 62-year-old male with a 6-cm left renal tumor in the medial parahilar segment with right renal unit functionally excluded, secondary to chronic obstruction due to ureteral lithiasis. Right ureteroscopy was performed with pneumatic lithotripsy. Despite localization and size of the tumor, left nephron-sparing surgery was performed in order to preserve renal function. Follow-up of the patient demonstrates no tumor activity. CONCLUSIONS: Open nephron-sparing surgery has been the standard treatment for small renal masses with peripheral localization; however, in specific cases with deteriorated renal function and tumors >5 cm close to the renal hilum, certain risk must be taken in order to perform this procedure that has proven to be highly effective in preserving renal function. Open nephron-sparing surgery represents a highly effective procedure in small renal masses with a nonfunctional contralateral kidney.

Efficacy of Tamsulosin, Oxybutynin, and their combination in the control of double-j stent-related lower urinary tract symptoms

ABSTRACT Introduction and objective Indwelling double J ureteral stents are used routinely in the resolution of ureteral obstruction caused by different etiologies. Evaluation of urinary symptoms related to double-J stent, indicate that these affect 73-90% of patients. We conducted a prospective, randomized study, to evaluate the efficacy of tamsulosin, oxybutinin and combination therapy in improving the urinary symptoms. Methods Patients who underwent ureteral stent placement after ureterolithotripsy (total 51), were randomized into three groups: Group I: Tamsulosin 0.4 mg. once per day(17 patients), Group II: Oxybutinin 5 mg. once per day (17 patients), Group III: Tamsulosin+ oxybutynin once per day (17 patients). All the groups received the drugs for three weeks and completed a Spanish validated Ureteral Stent Symptom Questionnaire (USSQ) at day 7 and 21. Results Repeated measures ANOVA showed mean urinary symptom index score was 22.3 vs. 15.5 in group three (p<0.001) at day 7 and 21 respectively. The mean work performance index was 6.6 vs 8.1 (p=0.049) favoring tamsulosin group, the mean sexual score was 0.5 vs 1.5 (p=0.03). Among additional problems the mean was 7.2 vs 6.2 (p=0.03). No significant difference was noted among pain and general health index. No side effects were reported. Conclusions Combination therapy with tamsulosin and oxybutynin improved irritative symptoms and work performance as well as sexual matters. Combination therapy should be considered for patients who complained of stent related symptoms.

Uso de reservorio continente tipo Indiana posterior a cistectomía radical por cáncer invasor de vejiga / Use of Indiana pouch after radical cistectomy for bladder invasive cancer

Objetivo: Comunicamos la experiencia del Hospital General de México en la realización del reservorio continente tipo Indiana en pacientes cistectomizados por cáncer invasor de vejiga. Material y métodos: De enero de 1995 a septiembre de 1997, se realizaron 24 derivaciones urinarias continentes tipo Indiana, 17 hombres y siete mujeres con una media de edad de 49.2 años. Se evaluó el tiempo quirúrgico, complicaciones inmediatas, mediatas y tardías, capacidad y funcionalidad del reservorio e integración del paciente a su vida social. Resultados: El padecimiento de base fue el cáncer vesical. El tiempo promedio de cirugía fue de 5.5 horas paraárealizar la cistectomía y la bolsa Indiana. Las complicaciones más frecuentes fueron: infección urinaria en cinco (20.8 por ciento) pacientes, acidosis metabólica en tres (12.5 por ciento); se presentó un caso de necrosis total de la bolsa, uno de litiasis en el reservorio, otro de dehiscencia de anastomosis ureterocolónica y dos con choque séptico. La funcionalidad del reservorio se evaluó clínica, radiológica y urodinámicamente. Conclusiones: La derivación urinaria continente tipo Indiana es una buena alternativa en pacientes cistectomizados. El dominio de la técnica disminuye en forma importante el tiempo quirúrgico empleado y las complicaciones.

Prostatectomía radical retropúbica en el tratamiento del carcinoma localizado de próstata. Experiencia en el Hospital General de México / Retropubic radical prostatectomy in the treatment of the in situ prostatic carcinoma. Experience at the Hospital General de Mexico

Introducción. La prostatectomía radical retropúbica es un procedimiento terapéutico que ha demostrado ser de mucho beneficio para el manejo de los pacientes con carcinoma de próstata en etapas confinadas al órgano. En nuestro país este método de tratamiento aún no es del dominio de toda la comunidad urológica. Objetivos. Presentar la experiencia de nuestro servicio en el manejo del carcinoma de próstata en etapas confinadas al órgano con este procedimiento quirúrgico. Material y métodos. Se revisaron los expedientes de 72 pacientes sometidos a este procedimiento quirúrgico, de los cuales 53 fueron elegibles para este estudio. En todos los casos se analizó edad, estadio clínico, estadio patológico, suma de Gleason, antígeno prostático específico pre y postoperatorio, complicaciones y supervivencia global, así como supervivencia libre de enfermedad. Resultados. Se encontró una diferencia importante en la estadificación clínica y la patológica; sólo 25 (47 por ciento) pacientes presentaron tumor confinado al órgano y 28 (53 por ciento) mostraron datos de infiltración de los tejidos periprostáticos. La gradación histopatológica tuvo una relación directamente proporcional con el estadio patológico definitivo y con el comportamiento biológico del tumor. El valor sérico del antígeno prostético específico postoperatorio presentó cifras menores de 0.2 ng/mL en los pacientes con control de la enfermedad. El seguimiento promedio de los sujetos fue de 38.1 meses. Se encontró una supervivencia global de 90.5 por ciento. La supervivencia global libre de enfermedad fue de 65 por ciento. Los pacientes con enfermedad confinada al órgano tuvieron una supervivencia libre de enfermedad de 88 por ciento; mientras que en los sujetos con enfermedad localmente avanzada fue solamente de 39 por ciento. Conclusiones. La prostatectomía radical retropúbica demostró ser un procedimiento muy útil para el tratamiento del carcinoma de próstata confinado a la glándula en la población estudiada. Los métodos de diagnóstico actuales aún permiten un alto porcentaje de subestadificación de pacientes con este padecimiento. La supervivencia libre de enfermedad está relacionada directamente con el estadio definitivo del padecimiento.

Mielolipoma de la glándula suprarrenal sintomático. Presentación de un caso y revisión de la literatura / Suprarenal symptomatic mielolipoma. clinical case and literature review

El mielolipoma de la glándula suprarrenal es un tumor raro, benigno, endocrinológicamente inactivo, cuya estructura histológica consiste de tejido adiposo maduro con focos de células hematopoyéticas. La mayoría de los casos reportados son pequeños y asintomáticos, descubiertos en forma incidental. Presentamos el caso de un paciente del sexo femenino cuyo diagnóstico fue establecido clínicamente al presentar sintomatología dolorosa y corroborado con estudios de imagen. Se presenta el manejo quirúrgico y la evolución postoperatoria. Se efectúa una revisión de las características clínicas de estos tumores, así como su perfil por imagen y opciones de tratamiento.

Uteroscopía: experiencia con 152 pacientes / Uteroscopy: experience with 152 patients

Se analizaron los expedientes clínicos de 152 pacientes atendidos en el servicio de urología y nefrología del Hospital General de México, entre el 27 de julio de 1987 y el 17 de octubre de 1991, a quienes se les realizó ureteroscopía en su mayoría por enfermedad litiásica y otros diagnósticos. Se estudiaron 161 unidades de las que 114 correspondieron al uréter inferior (70.8 por ciento), 17 unidades de uréter medio (10.5 por ciento), y 30 unidades de uréter superior (18.6 por ciento). El total de fracasos fue de 55 unidades, con éxito en 106

Prótesis testiculares de metilmetacrilato y silicón elaboradas en el Hospital General de México, SS: modelo experimental en animales / Metthyl meta-acrilate and silicone testicular prothesis manufactured in the Hospital General de Mexico, SS: experimental model in animals

Las prótesis testiculares utilizadas en México son importadas y de costo elevado y, por este motivo, la mayoría de los pacientes que se someten por diversos motivos a orquiectomia no reciben un implante protésico, lo que origina mal aspecto estético y repercusiones psicológicas, sobre todo en sujetos jóvenes. A causa de la imposibilidad del paciente y del hospital para adquirir prótesis importadas, se elaboró en esta institución un protocolo experimental de prótesis de testículo en animales de tres especies diferentes (perros, conejos y ratas), y se compararon cuatro tipos de materiales distintos, silicón de grado médico, silicón de grado industrial, metilmetacrilato autopolimerizable y metimetacrilato termocurable; la prótesis de estos materiales se implantaron individualmente en la bolsa escrotal después de la orquiectomía inguinal, salvo en las ratas, en las que se implantaron en la región de la cruz; se efectuó seguimiento hasta por un año para investigar tolerancia, biocompatibilidad, o toxicidad de estos materiales, y se observaron la reacción tisular local y la sistématica, tanto en forma clínica como por medio del estudio histológico de escroto, pulmón, hígado y riñón. Los resultados presentados en este documento son totales; se encontró que el metimetacrilato en sus dos variedades, autopolimerizable y termocurable, y el silicón de grados tanto médico como industrial fue bien tolerado por los perros (grupo I). Los conejos (grupo II) aceptación bien los implantes de metilmetacrilato y silicón en sus dos variedades. En las ratas (grupo III) se presentaron infecciones locales y sistématicas en 91.6 por ciento de los animales, lo que no sucedió en los grupos I y II; se decidió en consecuencia cambiar la técnica colocando la prótesis en la región de la cruz de la rata, y se observó que estos animales aceptaron bien los implantes protésicos en sus cuatro variedades.