Use of an acellular collagen-elastin matrix to support bladder regeneration in a porcine model of peritoneocystoplasty

Bladder reconstruction without using the intestine remains a challenge to this day despite the development of new biomaterials and cell cultures. Human bladder engineering is merely anecdotic, and mostly in vitro and animal studies have been conducted. In our study using a porcine model, we performed a bladder augmentation using an autologous parietal peritoneum graft (peritoneocystoplasty) and determined whether the attachment of an acellular collagen-elastin matrix (Group 1) or lack of (Group 2) had better histologic and functional results. Thus far, peritoneocystoplasty has rarely been performed or combined with a biomaterial. After 6 weeks, we observed different degrees of retraction of the new bladder wall in both groups, although the retraction was lower and the histological analysis showed more signs of regeneration (neoangiogenesis and less fibrosis) in Group 1 than when compared with Group 2. No transitional cells were found in the new bladder wall in any of the groups, and no differences were observed in the functional test results. Performing a peritoneocystoplasty is an easy and safe procedure. The data supports the benefit of an acellular collagen-elastin matrix to reinforce bladder regeneration. However, in our study we observed too much retraction of the new wall and the histologic results were not acceptable to consider it an appropriate cystoplasty technique

Clinical factors affecting semen improvement after microsurgical subinguinal varicocelectomy: which subfertile patients benefit from surgery?

Background: The exact mechanism of varicocele-related infertility is still elusive, therefore, the current challenges for its management lie in determining which patients stand to benefit most from surgical correction. The authors aimed to assess the clinical factors affecting semen improvement after left microsurgical subinguinal varicocelectomy (MSV) in relation to patient age, ultrasound varicocele grading (USVG), and presence of a right subclinical varicocele (RSV). Methods: From 2010 to 2017 a total of 228 infertile patients underwent left MSV for clinical varicocele. Descriptive statistics were used to describe the cohort and verify the surgical benefit in terms of semen improvement, in addition, subsets of patients were selected according to clinical covariates. Logistic regression modeling was applied to evaluate the presence of RSV, operative time, age, and USVG as explanatory variables. Results: Sperm concentration (SC), progressive sperm motility (PSM), and normal sperm morphology (NSM) increased significantly after surgery (p = 0.002; p = 0.011; p = 0.024; respectively). Mean SC improved after MSV in > 35 year-old patients and the grade 3 USVG group (p = 0.01; p = 0.02; respectively). Logistic regression modeling showed a that the probability of SC improvement was 76% lower in subjects presenting RSV (p = 0.011). In addition, patients with a grade 3 USVG presented a three-times greater probability of SC improvement compared with patients with a lower USVG (p = 0.035). In addition, older patients showed a greater probability of SC improvement after MSV (p = 0.041). Conclusions: MSV is an effective varicocele-related infertility treatment that should also be offered to older patients. In addition, patients with a higher USVG benefit from surgery. In infertile men with an RSV in association with a left clinical disease, a bilateral varicocele repair should be considered

Uso de una matriz de colágeno y elastina en la reparación de un defecto vesical con peritoneo parietal en modelo porcino

La reconstrucción vesical es el procedimiento realizado para sustituir o ampliar la vejiga, siendo el intestino el tejido utilizado en la práctica clínica habitual. A pesar de que su uso no está exento de complicaciones, apenas hay estudios clínicos en humanos que realicen reconstrucciones vesicales con materiales distintos al intestinal. Esta tesis -apoyada por dos artículos- quiere contribuir al desarrollo e investigación de un material que pueda reemplazar al intestino como gold standard de sustituto vesical. El artículo de revisión pretende describir y clasificar los diferentes materiales y cultivos celulares utilizados en ingeniería tisular vesical, así como revisar los estudios realizados en humanos. Tras la revisión de la literatura publicada, concluimos que la aproximación más realista para realizar una reconstrucción vesical experimental sería utilizar una matriz acelular o bien un polímero sintético y adherirle in vitro células uroteliales y musculares lisas autógenas, y/o células madre. El artículo original está basado en un proyecto experimental, en modelo porcino, en el que se realizaron ampliaciones vesicales utilizando un injerto de peritoneo parietal y se determinó si la adición de una matriz de colágeno y elastina reportaba mejores resultados histológicos y funcionales. Tras 6 semanas, los datos sugieren que la utilización de este tipo de biomaterial en un modelo porcino de peritoneocistoplastia favorece la regeneración tisular de la nueva pared. La sustitución o ampliación vesical sin utilizar el intestino continúa siendo un reto a día de hoy a pesar del progreso en la fabricación de biomateriales y del desarrollo de cultivos celulares. Para plantear una traslación clínica efectiva será necesario en el futuro realizar estudios bien diseñados, con mayor número de pacientes incluidos, más tiempo de seguimiento y estandarizar las pruebas funcionales de control.Bladder reconstructive surgery consists in creating a substitute or an enlargement to the bladder. Currently, human intestine is the tissue used into clinical practice to make it possible although it has many relevant drawbacks. Human bladder engineering with other materials is merely anecdotic, and mostly in vitro and animal studies have been conducted. This thesis -supported by two articles- works towards the research of a material that could replace the intestine as the gold standard tissue for bladder reconstruction. The aim of the review article was to describe and classify the different biomaterials and explain the human clinical studies done so far. We concluded that if we had to choose an experimental method to perform a bladder reconstruction, current evidence suggests to opt for an acellular matrix or a synthetic polymer, and seed it with autologous urothelial cells, autologous smooth muscle cells and/or stem cells. The original article consisted of an experimental project conducted in a porcine model, in which we performed bladder augmentations using an autologous parietal peritoneum graft and determined whether the attachment or not of an acellular collagen–elastin matrix had better histologic and functional results. After six weeks, our data supports the benefit of an acellular collagen–elastin matrix to reinforce bladder regeneration in a porcine model of peritoneocystoplasty. Bladder reconstruction without using the intestine is still an enormous challenge nowadays despite of the improvements in providing new materials and cell cultures. In order to be able to set apart the intestine as the material to substitute the bladder, it is necessary to continue performing more studies, enroll more patients, increase the follow-up time and standardize the functional tests

Uso de una matriz de colágeno y elastina en la reparación de un defecto vesical con peritoneo parietal en modelo porcino /

La reconstrucción vesical es el procedimiento realizado para sustituir o ampliar la vejiga, siendo el intestino el tejido utilizado en la práctica clínica habitual. A pesar de que su uso no está exento de complicaciones, apenas hay estudios clínicos en humanos que realicen reconstrucciones vesicales con materiales distintos al intestinal. Esta tesis -apoyada por dos artículos- quiere contribuir al desarrollo e investigación de un material que pueda reemplazar al intestino como gold standard de sustituto vesical. El artículo de revisión pretende describir y clasificar los diferentes materiales y cultivos celulares utilizados en ingeniería tisular vesical, así como revisar los estudios realizados en humanos. Tras la revisión de la literatura publicada, concluimos que la aproximación más realista para realizar una reconstrucción vesical experimental sería utilizar una matriz acelular o bien un polímero sintético y adherirle in vitro células uroteliales y musculares lisas autógenas, y/o células madre. El artículo original está basado en un proyecto experimental, en modelo porcino, en el que se realizaron ampliaciones vesicales utilizando un injerto de peritoneo parietal y se determinó si la adición de una matriz de colágeno y elastina reportaba mejores resultados histológicos y funcionales. Tras 6 semanas, los datos sugieren que la utilización de este tipo de biomaterial en un modelo porcino de peritoneocistoplastia favorece la regeneración tisular de la nueva pared. La sustitución o ampliación vesical sin utilizar el intestino continúa siendo un reto a día de hoy a pesar del progreso en la fabricación de biomateriales y del desarrollo de cultivos celulares. Para plantear una traslación clínica efectiva será necesario en el futuro realizar estudios bien diseñados, con mayor número de pacientes incluidos, más tiempo de seguimiento y estandarizar las pruebas funcionales de control.Bladder reconstructive surgery consists in creating a substitute or an enlargement to the bladder. Currently, human intestine is the tissue used into clinical practice to make it possible although it has many relevant drawbacks. Human bladder engineering with other materials is merely anecdotic, and mostly in vitro and animal studies have been conducted. This thesis -supported by two articles- works towards the research of a material that could replace the intestine as the gold standard tissue for bladder reconstruction. The aim of the review article was to describe and classify the different biomaterials and explain the human clinical studies done so far. We concluded that if we had to choose an experimental method to perform a bladder reconstruction, current evidence suggests to opt for an acellular matrix or a synthetic polymer, and seed it with autologous urothelial cells, autologous smooth muscle cells and/or stem cells. The original article consisted of an experimental project conducted in a porcine model, in which we performed bladder augmentations using an autologous parietal peritoneum graft and determined whether the attachment or not of an acellular collagen-elastin matrix had better histologic and functional results. After six weeks, our data supports the benefit of an acellular collagen-elastin matrix to reinforce bladder regeneration in a porcine model of peritoneocystoplasty. Bladder reconstruction without using the intestine is still an enormous challenge nowadays despite of the improvements in providing new materials and cell cultures. In order to be able to set apart the intestine as the material to substitute the bladder, it is necessary to continue performing more studies, enroll more patients, increase the follow-up time and standardize the functional tests

Use of an acellular collagen-elastin matrix to support bladder regeneration in a porcine model of peritoneocystoplasty

Bladder reconstruction without using the intestine remains a challenge to this day despite the development of new biomaterials and cell cultures. Human bladder engineering is merely anecdotic, and mostly in vitro and animal studies have been conducted. In our study using a porcine model, we performed a bladder augmentation using an autologous parietal peritoneum graft (peritoneocystoplasty) and determined whether the attachment of an acellular collagen-elastin matrix (Group 1) or lack of (Group 2) had better histologic and functional results. Thus far, peritoneocystoplasty has rarely been performed or combined with a biomaterial. After 6 weeks, we observed different degrees of retraction of the new bladder wall in both groups, although the retraction was lower and the histological analysis showed more signs of regeneration (neoangiogenesis and less fibrosis) in Group 1 than when compared with Group 2. No transitional cells were found in the new bladder wall in any of the groups, and no differences were observed in the functional test results. Performing a peritoneocystoplasty is an easy and safe procedure. The data supports the benefit of an acellular collagen-elastin matrix to reinforce bladder regeneration. However, in our study we observed too much retraction of the new wall and the histologic results were not acceptable to consider it an appropriate cystoplasty technique

Clinical factors affecting semen improvement after microsurgical subinguinal varicocelectomy : which subfertile patients benefit from surgery?

The exact mechanism of varicocele-related infertility is still elusive, therefore, the current challenges for its management lie in determining which patients stand to benefit most from surgical correction. The authors aimed to assess the clinical factors affecting semen improvement after left microsurgical subinguinal varicocelectomy (MSV) in relation to patient age, ultrasound varicocele grading (USVG), and presence of a right subclinical varicocele (RSV). From 2010 to 2017 a total of 228 infertile patients underwent left MSV for clinical varicocele. Descriptive statistics were used to describe the cohort and verify the surgical benefit in terms of semen improvement, in addition, subsets of patients were selected according to clinical covariates. Logistic regression modeling was applied to evaluate the presence of RSV, operative time, age, and USVG as explanatory variables. Sperm concentration (SC), progressive sperm motility (PSM), and normal sperm morphology (NSM) increased significantly after surgery (p = 0.002; p = 0.011; p = 0.024; respectively). Mean SC improved after MSV in ⩾35 year-old patients and the grade 3 USVG group (p = 0.01; p = 0.02; respectively). Logistic regression modeling showed a that the probability of SC improvement was 76% lower in subjects presenting RSV (p = 0.011). In addition, patients with a grade 3 USVG presented a three-times greater probability of SC improvement compared with patients with a lower USVG (p = 0.035). In addition, older patients showed a greater probability of SC improvement after MSV (p = 0.041). MSV is an effective varicocele-related infertility treatment that should also be offered to older patients. In addition, patients with a higher USVG benefit from surgery. In infertile men with an RSV in association with a left clinical disease, a bilateral varicocele repair should be considered