Robotic Near-Total Pancreatectomy for Nesidioblastosis after Bariatric Surgery.

Postprandial symptoms of neuroglycopenia after bariatric surgery may result as a consequence of endogenous hyperinsulinemic hypoglycemia (nesidioblastosis) not dumping syndrome. Pancreatectomy is an acceptable treatment for this condition. We present the video of a case of near-total distal robotic pancreactectomy for the treatment of nesidioblastosis after Roux-en-Y gastric bypass. Robotic pancreatectomy is an alternative to the treatment of nesidioblastosis after Roux-en-Y gastric bypass.

Inducible nitric oxide synthase inhibition increases MMP-2 activity leading to imbalance between extracellular matrix deposition and degradation after polypropylene mesh implant.

Prosthetic mesh implants are commonly used to correct abdominal wall defects. However, success of the procedure is conditioned by an adequate inflammatory response to the device. We hypothesized that nitric oxide produced by nitric oxide synthase 2 (NOS2) and MMP-2 and -9 participate in response induced by mesh implants in the abdominal wall and, consequently, affect the outcome of the surgical procedure. In the first step, temporal inflammatory markers profile was evaluated. Polypropylene meshes were implanted in the peritoneal side of the abdominal wall of C57Black mice. After 2, 4, 7, 15, and 30 days, tissues around the mesh implant were collected and inflammatory markers were analyzed. In the second step, NOS2 activity was inhibited with nitro-L-arginine methyl ester (L-NAME). Samples were collected after 15 days (when inflammation was reduced), and the inflammatory and tissue remodeling markers were investigated. Polypropylene mesh implant induced a pro-inflammatory environment mediated by intense MMP-2 and -9 activities, NO release, and interleukin-1ß production peaking in 7 days and gradually decreasing after 15 days. NOS2 inhibition increased MMP-2 activity and resulted in a higher visceral adhesion incidence at the mesh implantation site when compared with non-treated animals that underwent the same procedure. We conclude that NOS2-derived NO is crucial for adequate response to polypropylene mesh implant integration in the peritoneum. NO deficiency results in an imbalance between extracellular matrix deposition/degradation contributing to visceral adhesions incidence.

Nitric oxide modulates metalloproteinase-2, collagen deposition and adhesion rate after polypropylene mesh implantation in the intra-abdominal wall.

Prosthetic meshes are commonly used to correct abdominal wall defects. However, the inflammatory reaction induced by these devices in the peritoneum is not completely understood. We hypothesized that nitric oxide (NO), produced by nitric oxide synthase 2 (NOS2) may modulate the response induced by mesh implants in the abdominal wall and, consequently, affect the outcome of the surgical procedure. Polypropylene meshes were implanted in the peritoneal side of the abdominal wall in wild-type and NOS2-deficient (NOS2(-/-)) mice. After 15 days tissues around the mesh implant were collected, and inflammatory markers (the cytokine interleukin 1ß (IL-1ß) and NO) and tissue remodeling (collagen and metalloproteinases (MMP) 2 and 9) were analyzed. The lack of NOS2-derived NO induced a higher incidence of visceral adhesions at the mesh implantation site compared with wild-type mice that underwent the same procedure (P<0.05). Additionally, higher levels of IL-1ß were present in the mesh-implanted NOS2(-/-) animals compared with control and wild-type mice. Mesh implantation induced collagen I and III deposition, but in smaller amounts in NOS2(-/-) mice. MMP-9 activity after the surgical procedure was similarly increased in both groups. Conversely, MMP-2 activity was unchanged in mesh-implanted wild-type mice, but was significantly increased in NOS2(-/-) mice (P<0.01), due to decreased S-nitrosylation of the enzyme in these animals. We conclude that NOS2-derived NO is crucial for an adequate response to and integration of polypropylene mesh implants in the peritoneum. NO deficiency results in a prolonged inflammatory reaction to the mesh implant, and reduced collagen deposition may contribute to an increased incidence of visceral adhesions.

Laparoscopic evaluation of abdominal adhesions with different prosthetic meshes in rabbits.

BACKGROUND: The use of prosthetic materials to reinforce the abdominal wall is associated with a low index of recurrence; however, intraperitoneal placement of a foreign body may lead to adhesions. The present investigation was designed to determine adhesion formation with commercially available meshes implanted laparoscopically in rabbits. METHODS: Three different meshes were implanted laparoscopically in 24 rabbits: polypropylene (mesh A), polypropylene and sodium hyaluronate-carboxymethylcellulose (mesh B), and polypropylene and expanded polytetrafluoroethylene (mesh C). Sites of implantation for each mesh (the left lower quadrant, right lower quadrant, and lower midline) were randomly determined so that every rabbit had all 3 meshes implanted. All animals underwent diagnostic laparoscopy after 28 days to grade adhesions and histological analysis of inflammation. RESULTS: Adhesions were noticed in 46 of the 72 meshes implanted (64%). The number of adhesions was higher for mesh C (87.5%) compared with meshes A (62.5%) and B (41.6%). The severity of adhesions was also higher for mesh C (grade I in 14, II in 6, and III in 1) compared with mesh A (grade I in 10, II in 4, and III in 1 case) and B (all of them grade II). Histological inflammatory reaction was classified as mild in 23 cases of mesh A, 15 of mesh B, and 23 of mesh C. A moderate reaction was found in 1 case of mesh A, 4 cases of mesh B, and 1 case of mesh C. Severe reaction was induced in 5 cases of mesh B. Mesh B induced a higher inflammatory reaction compared with the other meshes. CONCLUSIONS: All meshes induced adhesions of different grades. Mesh B had fewer adhesions and more intense inflammation them did the others.

Comparative study of inflammatory response and adhesions formation after fixation of different meshes for inguinal hernia repair in rabbits

OBJETIVO: Avaliar a resposta inflamatória e a formação de aderências das próteses de polipropileno e polipropileno associado a poliglactina sintética (Vypro®) implantadas no espaço pré-peritoneal de coelhos. MÉTODOS: Foram utilizados 14 coelhos albinos linhagem Nova Zelândia com três meses de idade, machos com peso variando de 2000 a 2500 gramas. O acesso à cavidade se deu por incisão mediana abaixo do apêndice xifóide com oito centímetros de extensão. Realizou-se o implante da tela de polipropileno no flanco esquerdo com um ponto de polipropileno em cada extremidade da prótese. No flanco direito a tela Vypro® foi fixada da mesma forma com pontos de polipropileno. A laparoscopia foi realizada 28 dias após o primeiro procedimento para avaliação de aderências intracavitárias. As próteses juntamente com o peritônio, musculatura e aponeurose adjacente foram retiradas em blocos individuais. Cada peça foi imersa em solução tamponada de formaldeido a 10% e encaminhada ao patologista. RESULTADOS: Todos os animais tiveram boa evolução pós-operatória não havendo infecção das incisões cirúrgicas ou óbito dos coelhos. Das quatorze próteses Prolene implantadas no peritônio intacto de coelho, em onze (78,6%) houve formação de aderências Das quatorze próteses Vypro®implantadas no peritônio intacto de coelho, em doze (85,7%) houve formação de aderências. Comparando as duas próteses entre si não houve diferença significante quanto ao numero de aderências formadas. Em relação a avaliação microscópica, nas próteses VYPRO® a reação granulomatosa do tipo corpo estranho e a fibrose foram predominantemente moderadas. Já a inflamação inespecífica foi proporcionalmente leve e moderada A inflamação inespecífica foi menos intensa nas próteses de polipropileno. CONCLUSÃO: Ambas as próteses implantadas na cavidade peritoneal de coelhos promovem a formação de aderências de forma semelhante. As próteses de polipropileno e associado a poliglactina promovem maior fibrose, apresentando melhor incorporação aos tecidos.

Comparative study of inflammatory response and adhesions formation after fixation of different meshes for inguinal hernia repair in rabbits.

PURPOSE: Compare, in a rabbit model, the inflammatory response and adhesions formation following surgical fixation of polypropilene and Vypro mesh in the inguinal preperitoneal space. METHODS: Fourteen male New Zealand rabbits, weighing between 2.000 to 2.500 g were used. A midline incision was made and the peritoneal cavity was exposed. The 2.0 x 1.0 cm polypropylene mesh was fixed in the left flank and secured to the margins with 3-0 prolene in a separate pattern. In the right flank, a 2.0 x 1.0 cm Vypro II mesh was sewn in the same way. After the post surgical period, the animals were again anesthetized and underwent laparoscopic approach, in order to identify and evaluate adhesions degree. Both fixed prosthesis were excised bilaterally with the abdominal wall segment, including peritoneum, aponeurosis and muscle and sent to a pathologist. RESULTS: Operative time ranged from 15 to 25 minutes and no difficulties in applying the mesh were found. From the 14 polypropylene meshes fixed to the intact peritoneum, 11 had adhesions to the abdominal cavity (78.6%). Concerning Vypro mesh, 12 animals developed adhesions from the 14 with mesh fixation (85.7%). Histological examination of tissues harvested revealed fibroblasts, collagen, macrophages and lymphocytes between the threads of the mesh. CONCLUSION: Polypropylene and Vypro mesh, when implanted in the peritoneal cavity of rabbits provoke similar amount of adhesions. Vypro mesh tissues had higher fibrosis resulting in better mesh incorporation to the abdominal wall.

Safety of cystic duct clipping in healthy and cirrhotic livers: a cadaveric study.

BACKGROUND AND OBJECTIVES: Biliary leakage through the cystic duct stump due to clip dislodgement has been a concern since the advent of the laparoscopic cholecystectomy. The authors proposed a cadaveric model to test the safety of cystic duct clipping in a hypertensive biliary tract in healthy and cirrhotic livers. METHODS: Twenty fresh cadavers were studied (5 cirrhotic, 15 healthy). Open cholecystectomy was performed and the cystic duct clipped with commercially available titanium clips. The distal common bile duct was catheterized to allow infusion of water and pressure measurement. RESULTS: Increased pressure in the bile duct resulted in back diffusion into the liver, preventing reaching high-pressure levels. Only 1 clip was dislodged in this situation, in a cirrhotic liver with a large cystic duct. As a second experiment, the hepatic hilum was clamped to allow higher pressures of the biliary tree (500 mm Hg). In this situation, no clip was dislodged. CONCLUSIONS: We have established the safety of cystic duct clipping in healthy and cirrhotic livers; however, bigger clips or alternative methods to seal the duct may be necessary in larger ducts.

Efeitos da tela de polipropileno no testículo, epidídimo e ducto deferentes de cäes / Effects of the polypropilene mesh in the testicle, epididimus and ductus deferens of dogs

Objetivo: Investigar os efeitos da tela sintética sobre o testículo, epidídimo e ducto deferente de cäes. Métodos: Foram utilizados 10 cäes, machos, adultos, pesando entre 9 e 12 kg. Os animais, após realizada anestesia, foram submetidos à laparoscopia com formaçäo de pneumoperitônio por incisäo em linha mediana. Era entäo fixada tela de polipropileno, de dimensöes 2,5X3,5 cm² na regiäo inguinal esquerda do cäo em contato direto com o funículo espermático, com o uso de grampos metálicos, sem dissecar a regiäo. O lado direito, sem colocaçäo de tela, serviu de controle. O procedimento tinha duraçäo de 15 minutos. Após observaçäo pós-operatória de 30 dias, os animais eram novamente anestesiados e reoperados sendo o testículo e ducto deferente retirados e enviados para análise histológica. Análise estatística foi realizada com os dados obtidos desta análise. Resultados: No lado esquerdo, as secçöes histológicas de testículo revelaram focalmente, diminuiçäo da espermatogênese e processo degenerativo em 20 por cento dos animais. No epidídimo, observou-se inflamaçäo crônica e dilataçäo dos túbulos seminíferos em 70 por cento. No ducto deferente foi observado processo inflamatório crônico em 60 por cento dos cäes. Näo foram verificadas alteraçöes histológicas no lado contralateral. Conclusäo: A tela de polipropileno em contato com o funículo espermático de cäes provoca alteraçöes histológicas com discreta reduçäo da espermatogênese.

Proposiçäo de videolaparoscopia em ratos / Videolaparoscopy proposition in rats

Os autores apresentam a possibilidade do uso da videolaparoscopia em ratos. Foram utilizados 10 ratos Wistar. Empregaram uma óptica de 3mm, 30 graus, usada em artroscopia. Obtiveram boa visibilização dos órgãos da cavidade peritoneal. A introdução de agulhas especiais e instrumentos delicados permitiram realizar os procedimentos operatórios. O modelo experimental proposto tornou-se viável, em ratos.