Marco Pereira-Sampaio - Academia.edu (original) (raw)

Papers by Marco Pereira-Sampaio

Research paper thumbnail of Anatomical Study and Proportional Analysis of the Pig Spleen Arterial Segments

Cells Tissues Organs, 2006

Research paper thumbnail of Glomerular loss after renal radiofrequency ablation are comparable to 30 minutes of warm ischemia

Journal of endourology, Jan 22, 2017

To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequenc... more To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia. Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia. Eight animals were allocated in the ischemia group, which had the left renal hilum clamped for 30 minutes under laparoscopic access. Ten animals were submitted to RFA of the left kidney lower pole, under laparoscopic visualization. Animals were euthanized 21 days after surgery, when kidneys were collected. Fragments of the upper pole of the left kidney were processed for morphometric analysis. Right kidney was used as self-controls for each animal. Glomerular volumetric density (Vv[glom]); volume-weighted glomerular volume (VWGV); and glomerular density were quantified by stereological methods and compared by Student´s-t-test and one-way-ANOVA with Dunnett&#39...

Research paper thumbnail of Glomerular Morphology and Renal Function after Warm Ischemia by Main Artery or Selective Clamping in a Porcine Model

Urologia internationalis, Jan 30, 2017

The study aimed to evaluate the ischemic and non-ischemic areas after selective arterial occlusio... more The study aimed to evaluate the ischemic and non-ischemic areas after selective arterial occlusion by using stereological analysis of glomeruli, and to compare them with main arterial clamping and sham-operated animals. Twenty-four male pigs were used in the study. The animals were divided into 3 groups with 8 animals in each as follows: group sham, submitted to laparoscopic dissection of the renal pedicle but not submitted to ischemia; group arterial (A), submitted to left renal artery clamping; and group selective (S), submitted to left renal artery caudal branch occlusion. Groups A and S underwent 30 min of warm ischemia. Left and right kidneys were collected after 21 days and renal fragments were processed for stereological evaluation. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and glomerular density were measured. Serum creatinine and urea were assessed preoperatively, 10 days after surgery, and before euthanasia. There was no significant difference amo...

Research paper thumbnail of Effects of castration on penile extracellular matrix morphology in domestic cats

Journal of Feline Medicine and Surgery, 2017

Objectives This study was undertaken to verify the possible modifications caused by hormonal depr... more Objectives This study was undertaken to verify the possible modifications caused by hormonal deprivation in the extracellular matrix in the penises of neutered cats. Methods Twenty-seven penises from domestic shorthair cats were collected: 14 samples from intact cats and 13 from neutered cats. Sections were stained with Weigert's resorcin-fuchsin, hematoxylin and eosin, and picrosirius red. Histomorphometric analysis was performed using light microscopy and image analysis software. The following parameters were analyzed: density of the elastic fibers and collagen fibers in the corpus spongiosum; density of the elastic fibers in the tunica albuginea of the corpus cavernosum and the tunica albuginea of the corpus spongiosum; luminal area of the urethra; area of the corpus spongiosum; area of the corpus cavernosum; and thickness of the urethral epithelium. The data were analyzed using the Shapiro-Wilk test to verify the normal distribution, and groups were compared using Student's t-test; P <0.05 indicated statistically significant differences. Results Significant differences were observed between intact cats and neutered cats in the density of elastic fibers in the tunica albuginea of the corpus cavernosum (8.13% ± 1.38% vs 3.11% ± 0.66%), tunica albuginea of the corpus spongiosum (4.37% ± 1.08% vs 3.30% ± 1.01%) and corpus spongiosum (6.28% ± 3.03% vs 4.10% ± 2.19%), and density of collagen fibers in the corpus spongiosum (34.11% ± 10.86% vs 44.21% ± 12.72%). Conclusions and relevance The results show a significant decrease in the density of the elastic fibers and a significant increase of the density of the collagen fibers in the corpus spongiosum in neutered animals. This suggests that the compliance of the periurethral region is reduced, and these changes could be a predisposing factor for urethral obstructive disease.

Research paper thumbnail of Glomerular loss after arteriovenous and arterial clamping for renal warm ischemia in a swine model

Acta Cirurgica Brasileira, 2016

To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model. T... more To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model. Twenty four pigs were divided into Group Sham (submitted to all surgical steps except the renal ischemia), Group AV (submitted to 30 minutes of warm ischemia by arteriovenous clamping of left kidney vessels), and Group A (submitted to 30 minutes of ischemia by arterial clamping). Right kidneys were used as controls. Weigh, volume, cortical volume, glomerular volumetric density (Vv[Glom]), volume-weighted glomerular volume (VWGV), and the total number of glomeruli were measured for each organ. Group AV showed a 24.5% reduction in its left kidney Vv[Glom] and a 25.4% reduction in the VWGV, when compared to the right kidney. Reductions were also observed when compared to kidneys of sham group. There was a reduction of 19.2% in the total number of glomeruli in AV kidneys. No difference was observed in any parameters analyzed on the left kidneys from group A. Renal warm ischemia of 30 minutes by arterial clamping did not caused significant glomerular damage, but arteriovenous clamping caused significant glomerular loss in a swine model. Clamping only the renal artery should be considered to minimize renal injury after partial nephrectomies.

Research paper thumbnail of Two-part silicone mold. A new tool for flexible ureteroscopy surgical training

International braz j urol, 2016

Research paper thumbnail of Histomorphometric comparison of the human, swine, and ovine collecting systems

Anatomical record (Hoboken, N.J. : 2007), Jan 25, 2016

The ovine kidney has been recently determined to be a better model than the swine kidney for the ... more The ovine kidney has been recently determined to be a better model than the swine kidney for the study of collecting system healing after partial nephrectomy. However, there is no histological study comparing the collecting systems of these species. To compare human, swine, and ovine collecting systems using histomorphometry. The collecting systems of 10 kidneys from each species (human, swine, and ovine) were processed for histomorphometry. The thickness of the 3 layers (mucosal connective tissue, submucosal muscular, and adventitial connective tissue) were measured. The densities of smooth muscle fibers, elastic system fibers, and cells were also measured. Additionally, blood vessel density in the adventitial connective tissue was measured. Analysis of the collecting systems from the 3 species presented several differences. The adventitial connective tissue from the swine samples was thicker, with more blood vessels and smooth muscle fibers, compared with that from the human and o...

Research paper thumbnail of Anatomical relationship between the kidney collecting system and the intrarenal arteries in the sheep: Contribution for a new urological model

Anatomical record (Hoboken, N.J. : 2007), Jan 14, 2016

Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy... more Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy without closure. Recently, a study in sheep showed that partial nephrectomy without closure of the collecting system resulted in urinary leakage and urinoma. The aim of this study was to present detailed anatomical findings on the intrarenal anatomy of the sheep. Forty two kidneys were used to produce tridimensional endocasts of the collecting system together with the intrarenal arteries. A renal pelvis which displayed 11 to 19 (mean of 16) renal recesses was present. There were no calices present. The renal artery was singular in each kidney and gave two primary branches one to the dorsal surface and one to ventral surface. Dorsal and ventral branches of the renal artery were classified based on the relationship between their branching pattern and the collecting system as: type I (cranial and caudal segmental arteries), type II (cranial, middle and caudal segmental arteries) or type II...

Research paper thumbnail of The Sheep as A Model for Healing Studies after Partial Nephrectomy

Journal of Surgical Research, 2015

The pig has been considered the best model for renal surgery. However, recent research has demons... more The pig has been considered the best model for renal surgery. However, recent research has demonstrated that the kidney of pigs heals differently from that of humans. The objective of this study was to evaluate sheep as an alternative animal model for studying collecting system healing after laparoscopic partial nephrectomy. The caudal pole of the left kidney was removed from eight female adult domestic sheep using laparoscopic partial nephrectomy. Monopolar energy was used for hemostasis only in the parenchyma, avoiding coagulation near the collecting system, which was left opened. After 14 d, all animals were euthanized, and their left kidney was removed. Serum levels of urea and creatinine were assessed preoperatively and postoperatively (on days 2, 6, 10, and 14), and peritoneal fluid samples were collected during necropsy for urea and creatinine evaluation. An ex vivo retrograde pyelogram was performed, and a retrograde injection of methylene blue ink was administered to evaluate urinary leakage. Samples from the operated pole were analyzed using histologic methods. During necropsy, an urinoma surrounding the operated kidney was observed in one animal. Peritoneal fluid levels of urea and creatinine were elevated. Retrograde pyelograms exhibited contrast-medium extravasation through the operated pole in all kidneys. The opened collecting system was also confirmed by methylene blue ink injection. The operated pole was covered by collagenous tissue and adhered to adjacent organs. Sheep should be considered as an adequate experimental model for research on collecting system healing after partial nephrectomy.

Research paper thumbnail of Effects of Testicular Transfixation on Seminiferous Tubule Morphology and Sperm Parameters of Prepubertal, Pubertal, and Adult Rats

Theriogenology, 2015

Orchiopexy is performed as part of cryptorchidism and testicular torsion treatment. The inflammat... more Orchiopexy is performed as part of cryptorchidism and testicular torsion treatment. The inflammation caused by the needle and suture penetration has been suggested to be one of the possible causes of subfertility after parenchymal transfixation of the testicles. The purpose of the present study was to investigate testicular alterations after parenchymal transfixation sutures at different ages in rats. Prepubertal, pubertal, and adult rats were submitted to parenchymal suturing (without tying the knots, thus avoiding local ischemic injury) of the right testicle, which was maintained for 4 hours. All animals were subjected to euthanasia on completion of 14 weeks of life. The right testicles were studied as the sutured testicles, whereas the left organs were studied as contralateral. One age-matched control group of rats that was not submitted to any procedure was used for comparison. During euthanasia, sperm were collected from the tail of the epididymal and evaluated for concentration, motility, and viability. Samples from testicular tissue were collected for morphologic analysis. Sperm analysis indicated that only the adult operated animals presented reductions in motility (38.2% of adult vs. 54.1% of control; P = 0.02) and viability (16.6% of adult vs. 24.6% of control; P = 0.003). Several morphologic alterations were noted both in sutured and in contralateral testes at all ages. For instance, the seminiferous epithelium volumetric density of right testicles was reduced from 50.4% in controls to 32.3% in prepubertal operated animals, 45.3% in pubertal operated animals, and 39.4% in adult operated animals (P < 0.05). The seminiferous epithelium volumetric density was also reduced to 39.9% and 39.0% in contralateral testicles of animals operated before and after puberty, respectively (P < 0.05). The animals operated on before puberty and in adulthood showed more testicular morphologic alterations, as seminiferous tubule volumetric density, seminiferous tubule length, and tubular diameter were reduced only in prepubertal and/or adult operated animals. Testicular transfixation in rats led to important morphologic modifications in the ipsilateral and contralateral organs. These alterations were observed regardless of the age when surgery was performed, but they were milder in animals operated on during puberty. Orchiopexy techniques that do not involve the application of testicular transfixation sutures should be recommended.

Research paper thumbnail of MP28-07 Flexible Ureteroscopy Training. New Tool of Two-Part Silicone Mold (Cavities) Based on Real Human Kidneys Endocasts

The Journal of Urology, 2015

Research paper thumbnail of Pig Kidney: Anatomical Relationships Between the Renal Venous Arrangement and the Kidney Collecting System - Applied Study for Urological Research and Surgical Training

European Urology Supplements, 2006

Research paper thumbnail of Sinusoidal Constriction and Vascular Hypertrophy in the Diabetes-Induced Rabbit Penis

International braz j urol, 2013

Objective: To assess the morphological changes of penile vascular structures and the corpus caver... more Objective: To assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits. Materials and Methods: Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from DG received an intravenous injection of alloxan (100mg/kg) to induce the diabetes. Ten weeks after the induction of diabetes, all animals were euthanized. Two fragments of the penile shaft were harvested and samples were processed and paraffin embedded. Sections (5µm) were cut and stained for histological and immunohistochemical markers. Results: Nuclear protrusion toward the lumen, and cytoplasmic vacuolization were observed in the tunica intima of the dorsal artery of the penis in DG. The thicknesses of the tunica media increased significantly in DG (p = 0.0350). It was also observed a significant increase in the area of the tunica media (p = 0.0179). There was no significant change in smooth muscle cell density in the tunica media of the dorsal artery of the penis (p = 0.0855). The collagen fiber pattern of the tunica adventitia of the dorsal artery of the penis was different between the control and diabetic groups. There was a significant decrease in the area occupied by the cavernous sinuses in DG (p = 0.0013). Conclusion: Alloxan-induced diabetes mellitus in rabbits promotes important changes in penile vascular structures, thereby decreasing blood supply and affecting penile hemodynamics, leading to erectile dysfunction.

Research paper thumbnail of Does prolonged pneumoperitoneum affect the kidney? Oxidative stress, stereological and electron microscopy study in a rat model

International braz j urol, 2013

Research paper thumbnail of 502Proportional analysis of the kidney arterial segments in swine

European Urology Supplements, 2005

Research paper thumbnail of 1045 Dog kidney: Anatomical relationships between the intrarenal arteries and the kidney collecting system

European Urology Supplements, 2005

Research paper thumbnail of Pneumoperitoneum induces morphological alterations in the rat testicle

Acta Cirurgica Brasileira, 2013

To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum i... more To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model.

Research paper thumbnail of Morphological aspects of atrioventricular valves in the ostrich (Struthio camelus)

Research paper thumbnail of Kidney Healing After Laparoscopic Partial Nephrectomy Without Collecting System Closure in Pigs

Urology, 2011

To access the kidney healing after laparoscopic partial nephrectomy without closuring of the coll... more To access the kidney healing after laparoscopic partial nephrectomy without closuring of the collecting system in pigs.

Research paper thumbnail of Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis

Pesquisa Veterinária Brasileira, 2013

Ribeiro I.C.A., Abidu-Figueiredo M., Costa F.B., Pereira-Sampaio M.A. & Chagas M.A. 2013. Stereol... more Ribeiro I.C.A., Abidu-Figueiredo M., Costa F.B., Pereira-Sampaio M.A. & Chagas M.A. 2013. Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis. Pesquisa Veterinária Brasileira 33(Supl.1):107-112.

Research paper thumbnail of Anatomical Study and Proportional Analysis of the Pig Spleen Arterial Segments

Cells Tissues Organs, 2006

Research paper thumbnail of Glomerular loss after renal radiofrequency ablation are comparable to 30 minutes of warm ischemia

Journal of endourology, Jan 22, 2017

To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequenc... more To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia. Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia. Eight animals were allocated in the ischemia group, which had the left renal hilum clamped for 30 minutes under laparoscopic access. Ten animals were submitted to RFA of the left kidney lower pole, under laparoscopic visualization. Animals were euthanized 21 days after surgery, when kidneys were collected. Fragments of the upper pole of the left kidney were processed for morphometric analysis. Right kidney was used as self-controls for each animal. Glomerular volumetric density (Vv[glom]); volume-weighted glomerular volume (VWGV); and glomerular density were quantified by stereological methods and compared by Student´s-t-test and one-way-ANOVA with Dunnett&#39...

Research paper thumbnail of Glomerular Morphology and Renal Function after Warm Ischemia by Main Artery or Selective Clamping in a Porcine Model

Urologia internationalis, Jan 30, 2017

The study aimed to evaluate the ischemic and non-ischemic areas after selective arterial occlusio... more The study aimed to evaluate the ischemic and non-ischemic areas after selective arterial occlusion by using stereological analysis of glomeruli, and to compare them with main arterial clamping and sham-operated animals. Twenty-four male pigs were used in the study. The animals were divided into 3 groups with 8 animals in each as follows: group sham, submitted to laparoscopic dissection of the renal pedicle but not submitted to ischemia; group arterial (A), submitted to left renal artery clamping; and group selective (S), submitted to left renal artery caudal branch occlusion. Groups A and S underwent 30 min of warm ischemia. Left and right kidneys were collected after 21 days and renal fragments were processed for stereological evaluation. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and glomerular density were measured. Serum creatinine and urea were assessed preoperatively, 10 days after surgery, and before euthanasia. There was no significant difference amo...

Research paper thumbnail of Effects of castration on penile extracellular matrix morphology in domestic cats

Journal of Feline Medicine and Surgery, 2017

Objectives This study was undertaken to verify the possible modifications caused by hormonal depr... more Objectives This study was undertaken to verify the possible modifications caused by hormonal deprivation in the extracellular matrix in the penises of neutered cats. Methods Twenty-seven penises from domestic shorthair cats were collected: 14 samples from intact cats and 13 from neutered cats. Sections were stained with Weigert's resorcin-fuchsin, hematoxylin and eosin, and picrosirius red. Histomorphometric analysis was performed using light microscopy and image analysis software. The following parameters were analyzed: density of the elastic fibers and collagen fibers in the corpus spongiosum; density of the elastic fibers in the tunica albuginea of the corpus cavernosum and the tunica albuginea of the corpus spongiosum; luminal area of the urethra; area of the corpus spongiosum; area of the corpus cavernosum; and thickness of the urethral epithelium. The data were analyzed using the Shapiro-Wilk test to verify the normal distribution, and groups were compared using Student's t-test; P <0.05 indicated statistically significant differences. Results Significant differences were observed between intact cats and neutered cats in the density of elastic fibers in the tunica albuginea of the corpus cavernosum (8.13% ± 1.38% vs 3.11% ± 0.66%), tunica albuginea of the corpus spongiosum (4.37% ± 1.08% vs 3.30% ± 1.01%) and corpus spongiosum (6.28% ± 3.03% vs 4.10% ± 2.19%), and density of collagen fibers in the corpus spongiosum (34.11% ± 10.86% vs 44.21% ± 12.72%). Conclusions and relevance The results show a significant decrease in the density of the elastic fibers and a significant increase of the density of the collagen fibers in the corpus spongiosum in neutered animals. This suggests that the compliance of the periurethral region is reduced, and these changes could be a predisposing factor for urethral obstructive disease.

Research paper thumbnail of Glomerular loss after arteriovenous and arterial clamping for renal warm ischemia in a swine model

Acta Cirurgica Brasileira, 2016

To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model. T... more To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model. Twenty four pigs were divided into Group Sham (submitted to all surgical steps except the renal ischemia), Group AV (submitted to 30 minutes of warm ischemia by arteriovenous clamping of left kidney vessels), and Group A (submitted to 30 minutes of ischemia by arterial clamping). Right kidneys were used as controls. Weigh, volume, cortical volume, glomerular volumetric density (Vv[Glom]), volume-weighted glomerular volume (VWGV), and the total number of glomeruli were measured for each organ. Group AV showed a 24.5% reduction in its left kidney Vv[Glom] and a 25.4% reduction in the VWGV, when compared to the right kidney. Reductions were also observed when compared to kidneys of sham group. There was a reduction of 19.2% in the total number of glomeruli in AV kidneys. No difference was observed in any parameters analyzed on the left kidneys from group A. Renal warm ischemia of 30 minutes by arterial clamping did not caused significant glomerular damage, but arteriovenous clamping caused significant glomerular loss in a swine model. Clamping only the renal artery should be considered to minimize renal injury after partial nephrectomies.

Research paper thumbnail of Two-part silicone mold. A new tool for flexible ureteroscopy surgical training

International braz j urol, 2016

Research paper thumbnail of Histomorphometric comparison of the human, swine, and ovine collecting systems

Anatomical record (Hoboken, N.J. : 2007), Jan 25, 2016

The ovine kidney has been recently determined to be a better model than the swine kidney for the ... more The ovine kidney has been recently determined to be a better model than the swine kidney for the study of collecting system healing after partial nephrectomy. However, there is no histological study comparing the collecting systems of these species. To compare human, swine, and ovine collecting systems using histomorphometry. The collecting systems of 10 kidneys from each species (human, swine, and ovine) were processed for histomorphometry. The thickness of the 3 layers (mucosal connective tissue, submucosal muscular, and adventitial connective tissue) were measured. The densities of smooth muscle fibers, elastic system fibers, and cells were also measured. Additionally, blood vessel density in the adventitial connective tissue was measured. Analysis of the collecting systems from the 3 species presented several differences. The adventitial connective tissue from the swine samples was thicker, with more blood vessels and smooth muscle fibers, compared with that from the human and o...

Research paper thumbnail of Anatomical relationship between the kidney collecting system and the intrarenal arteries in the sheep: Contribution for a new urological model

Anatomical record (Hoboken, N.J. : 2007), Jan 14, 2016

Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy... more Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy without closure. Recently, a study in sheep showed that partial nephrectomy without closure of the collecting system resulted in urinary leakage and urinoma. The aim of this study was to present detailed anatomical findings on the intrarenal anatomy of the sheep. Forty two kidneys were used to produce tridimensional endocasts of the collecting system together with the intrarenal arteries. A renal pelvis which displayed 11 to 19 (mean of 16) renal recesses was present. There were no calices present. The renal artery was singular in each kidney and gave two primary branches one to the dorsal surface and one to ventral surface. Dorsal and ventral branches of the renal artery were classified based on the relationship between their branching pattern and the collecting system as: type I (cranial and caudal segmental arteries), type II (cranial, middle and caudal segmental arteries) or type II...

Research paper thumbnail of The Sheep as A Model for Healing Studies after Partial Nephrectomy

Journal of Surgical Research, 2015

The pig has been considered the best model for renal surgery. However, recent research has demons... more The pig has been considered the best model for renal surgery. However, recent research has demonstrated that the kidney of pigs heals differently from that of humans. The objective of this study was to evaluate sheep as an alternative animal model for studying collecting system healing after laparoscopic partial nephrectomy. The caudal pole of the left kidney was removed from eight female adult domestic sheep using laparoscopic partial nephrectomy. Monopolar energy was used for hemostasis only in the parenchyma, avoiding coagulation near the collecting system, which was left opened. After 14 d, all animals were euthanized, and their left kidney was removed. Serum levels of urea and creatinine were assessed preoperatively and postoperatively (on days 2, 6, 10, and 14), and peritoneal fluid samples were collected during necropsy for urea and creatinine evaluation. An ex vivo retrograde pyelogram was performed, and a retrograde injection of methylene blue ink was administered to evaluate urinary leakage. Samples from the operated pole were analyzed using histologic methods. During necropsy, an urinoma surrounding the operated kidney was observed in one animal. Peritoneal fluid levels of urea and creatinine were elevated. Retrograde pyelograms exhibited contrast-medium extravasation through the operated pole in all kidneys. The opened collecting system was also confirmed by methylene blue ink injection. The operated pole was covered by collagenous tissue and adhered to adjacent organs. Sheep should be considered as an adequate experimental model for research on collecting system healing after partial nephrectomy.

Research paper thumbnail of Effects of Testicular Transfixation on Seminiferous Tubule Morphology and Sperm Parameters of Prepubertal, Pubertal, and Adult Rats

Theriogenology, 2015

Orchiopexy is performed as part of cryptorchidism and testicular torsion treatment. The inflammat... more Orchiopexy is performed as part of cryptorchidism and testicular torsion treatment. The inflammation caused by the needle and suture penetration has been suggested to be one of the possible causes of subfertility after parenchymal transfixation of the testicles. The purpose of the present study was to investigate testicular alterations after parenchymal transfixation sutures at different ages in rats. Prepubertal, pubertal, and adult rats were submitted to parenchymal suturing (without tying the knots, thus avoiding local ischemic injury) of the right testicle, which was maintained for 4 hours. All animals were subjected to euthanasia on completion of 14 weeks of life. The right testicles were studied as the sutured testicles, whereas the left organs were studied as contralateral. One age-matched control group of rats that was not submitted to any procedure was used for comparison. During euthanasia, sperm were collected from the tail of the epididymal and evaluated for concentration, motility, and viability. Samples from testicular tissue were collected for morphologic analysis. Sperm analysis indicated that only the adult operated animals presented reductions in motility (38.2% of adult vs. 54.1% of control; P = 0.02) and viability (16.6% of adult vs. 24.6% of control; P = 0.003). Several morphologic alterations were noted both in sutured and in contralateral testes at all ages. For instance, the seminiferous epithelium volumetric density of right testicles was reduced from 50.4% in controls to 32.3% in prepubertal operated animals, 45.3% in pubertal operated animals, and 39.4% in adult operated animals (P < 0.05). The seminiferous epithelium volumetric density was also reduced to 39.9% and 39.0% in contralateral testicles of animals operated before and after puberty, respectively (P < 0.05). The animals operated on before puberty and in adulthood showed more testicular morphologic alterations, as seminiferous tubule volumetric density, seminiferous tubule length, and tubular diameter were reduced only in prepubertal and/or adult operated animals. Testicular transfixation in rats led to important morphologic modifications in the ipsilateral and contralateral organs. These alterations were observed regardless of the age when surgery was performed, but they were milder in animals operated on during puberty. Orchiopexy techniques that do not involve the application of testicular transfixation sutures should be recommended.

Research paper thumbnail of MP28-07 Flexible Ureteroscopy Training. New Tool of Two-Part Silicone Mold (Cavities) Based on Real Human Kidneys Endocasts

The Journal of Urology, 2015

Research paper thumbnail of Pig Kidney: Anatomical Relationships Between the Renal Venous Arrangement and the Kidney Collecting System - Applied Study for Urological Research and Surgical Training

European Urology Supplements, 2006

Research paper thumbnail of Sinusoidal Constriction and Vascular Hypertrophy in the Diabetes-Induced Rabbit Penis

International braz j urol, 2013

Objective: To assess the morphological changes of penile vascular structures and the corpus caver... more Objective: To assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits. Materials and Methods: Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from DG received an intravenous injection of alloxan (100mg/kg) to induce the diabetes. Ten weeks after the induction of diabetes, all animals were euthanized. Two fragments of the penile shaft were harvested and samples were processed and paraffin embedded. Sections (5µm) were cut and stained for histological and immunohistochemical markers. Results: Nuclear protrusion toward the lumen, and cytoplasmic vacuolization were observed in the tunica intima of the dorsal artery of the penis in DG. The thicknesses of the tunica media increased significantly in DG (p = 0.0350). It was also observed a significant increase in the area of the tunica media (p = 0.0179). There was no significant change in smooth muscle cell density in the tunica media of the dorsal artery of the penis (p = 0.0855). The collagen fiber pattern of the tunica adventitia of the dorsal artery of the penis was different between the control and diabetic groups. There was a significant decrease in the area occupied by the cavernous sinuses in DG (p = 0.0013). Conclusion: Alloxan-induced diabetes mellitus in rabbits promotes important changes in penile vascular structures, thereby decreasing blood supply and affecting penile hemodynamics, leading to erectile dysfunction.

Research paper thumbnail of Does prolonged pneumoperitoneum affect the kidney? Oxidative stress, stereological and electron microscopy study in a rat model

International braz j urol, 2013

Research paper thumbnail of 502Proportional analysis of the kidney arterial segments in swine

European Urology Supplements, 2005

Research paper thumbnail of 1045 Dog kidney: Anatomical relationships between the intrarenal arteries and the kidney collecting system

European Urology Supplements, 2005

Research paper thumbnail of Pneumoperitoneum induces morphological alterations in the rat testicle

Acta Cirurgica Brasileira, 2013

To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum i... more To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model.

Research paper thumbnail of Morphological aspects of atrioventricular valves in the ostrich (Struthio camelus)

Research paper thumbnail of Kidney Healing After Laparoscopic Partial Nephrectomy Without Collecting System Closure in Pigs

Urology, 2011

To access the kidney healing after laparoscopic partial nephrectomy without closuring of the coll... more To access the kidney healing after laparoscopic partial nephrectomy without closuring of the collecting system in pigs.

Research paper thumbnail of Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis

Pesquisa Veterinária Brasileira, 2013

Ribeiro I.C.A., Abidu-Figueiredo M., Costa F.B., Pereira-Sampaio M.A. & Chagas M.A. 2013. Stereol... more Ribeiro I.C.A., Abidu-Figueiredo M., Costa F.B., Pereira-Sampaio M.A. & Chagas M.A. 2013. Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis. Pesquisa Veterinária Brasileira 33(Supl.1):107-112.