Inferior Vena Cava Repair Using Diaphragm in Animal Model.

BACKGROUND: Repair and reconstruction of the vena cava with an autologous vein requires multiple incisions. Prosthetic material is linked with an increased risk of infection and thrombosis. Therefore in this study, we created an animal model of vena cava repair using the diaphragm. The objective of this study is to assess the feasibility and outcomes of using diaphragm for the repair and replacement of the inferior vena cava (IVC) after resection of a part of the infrarenal IVC in an animal model, as it may be encountered in trauma patients and extensive tumors of retroperitoneum. METHODS: Five healthy dogs of both sexes were prepared. After general anesthesia and laparotomy, a 1 cm width with 4 cm length defect was arranged on anterior aspect of the infrarenal IVC, subsequently, the anterior aspect of the right diaphragm with 1 cm width and 4 cm length was resected and was anastomosed to cover the defect of the IVC as a patch graft, with the pleural side of the diaphragm facing the luminal aspect and the peritoneal side on the outside. The observation period was 6 weeks. RESULTS: All of the IVCs were macroscopically patent without thrombosis and stenosis. Pathologic assay revealed complete endothelialization of diaphragm. One dog died at the third night of operation without distinct reason. CONCLUSIONS: The diaphragm is an accessible and safe option in the repair and reconstruction of IVC particularly when restrictions exist for the use of prosthetic material in a contaminated space of the abdomen.

Morphological Evaluation of the Tissue Reaction to Subcutaneous Implantation of Decellularized Matrices.

Based on the data of morphological analysis, we performed histological evaluation of rat tissue reaction to subcutaneous implantation of decellularized matrices of intrathoracic organs and tissues. Cell composition of the inflammatory infiltrate was analyzed, and the dynamics of macrophage and T and B lymphocyte content was assessed on days 7 and 14 of the experiment. It was found that the reaction to implantation depended not only on the quality of decellularization and efficiency of removal of antigen molecules, but also on the original histological structure and quality of preimplantation processing of the transplant.

Orthotopic transplantation of a tissue engineered diaphragm in rats.

The currently available surgical options to repair the diaphragm are associated with significant risks of defect recurrence, lack of growth potential and restored functionality. A tissue engineered diaphragm has the potential to improve surgical outcomes for patients with congenital or acquired disorders. Here we show that decellularized diaphragmatic tissue reseeded with bone marrow mesenchymal stromal cells (BM-MSCs) facilitates in situ regeneration of functional tissue. A novel bioreactor, using simultaneous perfusion and agitation, was used to rapidly decellularize rat diaphragms. The scaffolds retained architecture and mechanical properties and supported cell adhesion, proliferation and differentiation. Biocompatibility was further confirmed in vitro and in vivo. We replaced 80% of the left hemidiaphragm with reseeded diaphragmatic scaffolds. After three weeks, transplanted animals gained 32% weight, showed myography, spirometry parameters, and histological evaluations similar to native rats. In conclusion, our study suggested that reseeded decellularized diaphragmatic tissue appears to be a promising option for patients in need of diaphragmatic reconstruction.

Venous thromboembolism after diaphragm pacing in amyotrophic lateral sclerosis.

INTRODUCTION: Patients with amyotrophic lateral sclerosis (ALS) are prone to venous thromboembolism (VTE) and secondary complications. Because there is an increased incidence of VTE after surgical procedures, placement of a Diaphragm Pacing System (DPS) in ALS patients as treatment for respiratory muscle weakness could potentially increase the incidence of VTE, especially in patients with limited mobility. METHODS: We implanted a DPS in 10 ALS patients who met the criteria for this procedure. They underwent a preoperative evaluation as recommended by the guidelines. RESULTS: We report 2 patients with no symptoms of deep vein thrombosis (DVT) before the surgical procedure who then developed perioperative VTE. CONCLUSIONS: These patients highlight the need to consider preoperative screening for DVT and postoperative thromboprophylaxis in high-risk ALS patients who undergo DPS placement.

Tissue engineering in congenital diaphragmatic hernia.

Engineered diaphragmatic repair is emblematic of perinatal regenerative medicine and of the fetal tissue engineering concept. The alternative of a cellularized graft for the repair of a congenital diaphragmatic defect in the neonatal period is both biologically justifiable by the mechanisms behind diaphragmatic hernia recurrence as well as an ideal match for fetal mesenchymal stem cell-based constructs. It has been among the most developed experimental pursuits in neonatal tissue engineering, of which clinical application should be forthcoming.

Enxerto homólogo congelado de diafragma na correção dos defeitos da parede abdominal de ratos / Diaphragma frozen homograft for rats' abdominal wall defects repair

OBJETIVOS: Análise morfológica e biomecânica do enxerto homólogo congelado de diafragma para correção de defeito da parede abdominal em ratos. MÉTODOS: Os animais foram distribuidos em controle (20 ratos Wistar) e experimento (30 ratos Wistar). Os do grupo controle foram submetidos à laparotomia mediana e sutura da parede abdominal; já os do grupo experimento, à ressecção da parede abdominal e reconstrução com enxerto homólogo congelado de diafragma. Os animais foram submetidos à eutanásia no 3° e 6° mês de pós-operatório e avaliados quanto à presença de complicações pós-operatórias, integridade do enxerto, presença de aderências, avaliação tensiométrica, avaliação histopatológica com H/E e com sirius-red (colágeno tipo I e III). RESULTADOS: Houve integração do enxerto em todos os animais sem complicações. Aderências foram semehantes entre os grupos controle e experimento após três e seis meses. Observaram-se maior força máxima, força de ruptura e tensão nos animais do grupo experimento aos três meses de pós-operatório (p=0,001; p=0,012 e p=0,001, respectivamente). Na correlação entre as diferentes variáveis estudadas houve correlação estatisticamente significante entre força máxima e tensão nos grupos controle e experimento (p=0,001 e p= 0,001), e nos subgrupos três e seis meses (p=0,002 e p=0,001). Correlacionaram-se força máxima e colágeno tipo I (p=0,04) e Índice de Maturação do Colágeno (IMaC) e força máxima (p=0,03) ambos somente no grupo controle, mas nos subgrupos 3 e 6 meses (p=0,045 e p=0,038). O número de monomorfonucleares e força máxima também apresentou significância estatística tanto para o grupo controle quanto para o experimento (p=0,005 e p=0,004, respectivamente). CONCLUSÃO: O enxerto homólogo congelado de diafragma mostrou ser boa alternativa no reparo de grandes defeitos da parede abdominal em ratos.

OBJECTIVE: To analyse the morphology and biomechanics of diaphragma frozen homografts used for rats' abdominal wall defects repair. METHOD: Thirty wistar rats with abdominal wall resection and reconstruction using frozen diaphragma homografts were compared to twenty other rats submitted to abdominal wall incision and closure (control). Animals were euthanized after 3 and 6 months and abdominal walls were avaliated histologically with H/E and Picrosiriud Red staining and tensiometric evaluation. RESULTS: The tensiometric parameters were greater in the experimental group at 3 months after surgery. The percentage of mature collagen was significantly greater at 6 months after surgery in control and experimental groups. Tensiometric parameters and type I collagen as well maturation collagen index and rupture maximal strength were statistically correlated after 3 and 6 months. CONCLUSION: Frozen diaphragma homograft can be an alternative to repair the defects of abdominal wall.

[Diaphragm frozen homograft for rats' abdominal wall defects repair]. / Enxerto homólogo congelado de diafragma na correção dos defeitos da parede abdominal de ratos.

OBJECTIVE: To analyse the morphology and biomechanics of diaphragma frozen homografts used for rats' abdominal wall defects repair. METHOD: Thirty wistar rats with abdominal wall resection and reconstruction using frozen diaphragma homografts were compared to twenty other rats submitted to abdominal wall incision and closure (control). Animals were euthanized after 3 and 6 months and abdominal walls were avaliated histologically with H/E and Picrosiriud Red staining and tensiometric evaluation. RESULTS: The tensiometric parameters were greater in the experimental group at 3 months after surgery. The percentage of mature collagen was significantly greater at 6 months after surgery in control and experimental groups. Tensiometric parameters and type I collagen as well maturation collagen index and rupture maximal strength were statistically correlated after 3 and 6 months. CONCLUSION: Frozen diaphragma homograft can be an alternative to repair the defects of abdominal wall.

Reconstruction of thoracic esophagus with pediculated diaphragmatic flap in dogs.

PURPOSE: To verify whether pediculated diaphragmatic flaps were suitable to correct iatrogenic wounds in dog's esophagus injuries. METHODS: Seven dogs were submitted to resection of a segment of the esophageal wall, which was then corrected by suturing a pediculated diaphragm flap. Endoscopic evaluation of the esophageal wall was done forty days after the surgical procedure. RESULTS: Three animals died, one due to implant ischemia, caused by strangulation of the phrenic artery; other due to wound infection; and the last, due to mediastinitis. Scar retraction was observed, however, there was no stenosis, allowing the passage of a 9,8 mm probe with no difficulty. The limits between the implants and the native esophagus were indistinguishable, and the implant was covered by esophageal mucosa. CONCLUSION: The diaphragmatic flaps are suitable on the restoring of continuity in dog's thoracic esophagus.

Reconstruction of thoracic esophagus with pediculated diaphragmatic flap in dogs

PURPOSE: To verify whether pediculated diaphragmatic flaps were suitable to correct iatrogenic wounds in dog's esophagus injuries. METHODS: Seven dogs were submitted to resection of a segment of the esophagical wall, which was then corrected by suturing a pediculated diaphragm flap. Endoscopic evaluation of the esophagical wall was done forty days after the surgical procedure. RESULTS: Three animals died, one due to implant ischemia, caused by strangulation of the phrenic artery; other due to wound infection; and the last, due to mediastinitis. Scar retraction was observed, however, there was no stenosis, allowing the passage of a 9,8 mm probe with no difficulty. The limits between the implants and the native esophagus were indistinguishable, and the implant was covered by esophageal mucosa. CONCLUSION: The diaphragmatic flaps are suitable on the restoring of continuity in dog's thoracic esophagus.

OBJETIVO: Verificar se retalhos diafragmáticos pediculados seriam adequados para correção de defeitos iatrogênicos do esôfago do cão. MÉTODOS: Sete cães foram submetidos à ressecção de um segmento da parede esofágica, o qual foi corrigido por meio da sutura de um pedículo diafragmático pediculado. Um animal morreu devido à isquemia do implante causada pelo estrangulamento da artéria frênica, outro devido à infecção da ferida cutânea e outro devido a mediastinite. Aos 40 dias após o procedimento fez-se um exame endoscópico dos animais nos cães sobreviventes. RESULTADOS: Observou-se retração cicatricial sem repercutir em estenose, permitindo a passagem de sonda de 9,8 mm, sem dificuldade. Os limites entre os implantes e o esôfago nativo se apresentaram indistinguíveis e o implante estava recoberto por mucosa esofágica. CONCLUSÃO: Os retalhos diafragmáticos são adequados na restauração da continuidade do esôfago torácico do cão.

Creation of coronary sinus using left atrial diaphragm in the patient with cor triatriatum and unroofed coronary sinus.

Surgical correction of cor triatriatum with unroofed coronary sinus consisted of creation of the coronary sinus using the left atrial diaphragm and closure of the atrial septal defect in an adult patient. No materials other than intracardiac components were used to repair all anomalies.

The diaphragmatic flap: A multiuse material in thoracic surgery.

BACKGROUND: The use of diaphragmatic pedicle flaps for reconstructive procedures in thoracic surgery is not very popular. Nevertheless, it provides considerable advantages. METHODS: Our experience covers 10 years (1987-1997) with a total of 25 patients in whom the diaphragmatic flap was used for different purposes. In 6 patients we used the diaphragmatic flap to protect the bronchopleural fistula at its early onset, which was not beyond 12 hours from the clinical diagnosis. We performed prophylactic suture protection after neoadjuvant therapy in 9 high-risk patients who underwent pneumonectomy and in 2 who underwent sleeve lobectomy. Postpneumonectomy pericardial defect repair was performed in 4 patients. In another 4 patients the diaphragmatic flap was used after spontaneous (n = 2) and iatrogenic (n = 2) lesions of the esophagus after 24 to 72 hours. RESULTS: No perioperative mortality was recorded. Complications were mainly related to the severe preoperative conditions of the patients: arrhythmia, respiratory insufficiency, and empyema. We report only 2 cases of minimal persistent bleeding from the chest tube, which spontaneously ceased. For those patients who survived for more than 1 year (n = 11), no diaphragmatic hernias were recorded. Bronchopleural fistulas and pericardial defects healed in all instances. The diaphragmatic flap was also effective in bronchopleural fistula. A late fistula caused by cancer relapse at the bronchial stump developed in only one patient. Excellent repair was achieved in all patients with esophageal lesions. CONCLUSIONS: We conclude that the diaphragmatic flap can be considered a practical, safe, and redundant material particularly indicated for defect or fistula closure and for suture line protection in the thoracic cavity.

Comparison of omentum, pleura and diaphragm for tracheal autograft survival in rats.

Pleura, diaphragm, pericardial fat pad, intercostal muscles and omentum can be used to protect and revascularize the bronchial suture line. To compare the efficiency of pleura, diaphragm and omentum, an experimental study was designed. Heterotopic tracheal autotransplantation was performed in 15 rats. Animals were divided into three groups; omentum, diaphragm and pleura. Tracheal Segment Necrosis Scoring System was used for pathologic examinations. Pleural and diaphragmatic groups showed the least necrosis and there was significant statistical difference among these groups and omental group (P < 0.05). Our study showed that pleura and diaphragm could be used as safely as omentum for protection and survival of bronchial suture lines.

Heterotopic neogenesis of skeletal muscle induced in the adult rat diaphragmatic peritoneum: ultrastructural and transplantation studies.

During the course of a mild chemical peritonitis, new skeletal muscle fibers develop and persist over a twelve-month interval in the diaphragmatic peritoneum. Light and electron microscopic studies revealed that the ectopic fibers developed from myoblasts and myotubes to fully differentiated muscle cells in the same manner as normally situated skeletal muscle. The ectopic fibers were separated from the intrinsic muscle by dense connective tissue and an elastic lamina. Diaphragms taken from normal rats and transplanted to the omentum of isogeneic recipients also developed skeletal muscle neogenesis in the same ectopic location as in the normal diaphragm. Satellite cells, reactive fibroblasts in the peritoneum, mesenchymal stem cells or blood-borne myoblast precursor cells could be the source of these ectopic muscle fibers. The results of the present studies, however, cannot provide conclusive evidence for the origin of the new muscle fibers. Regardless of their source, the methods employed may represent a unique model for the development and prolonged maintenance of skeletal muscle fibers in a heterotopic location in vivo.

Early closure of the postpneumonectomy bronchopleural fistula by pedicled diaphragmatic flaps.

In the past, several methods for closure of postpneumonectomy bronchopleural fistula have been proposed. Herein we describe a technique to close a bronchopleural fistula using a mobilized diaphragmatic flap sutured directly to the fistula edges. This maneuver improves the blood supply to the bronchial stump and may reduce residual pleural cavity. To prevent bacterial contamination of the pleural space, the procedure should be performed immediately after the diagnosis.

The two stage tracheostomy as a safe technique in instances of severe coagulopathy.

A simple two stage tracheostomy procedure is described for use in respirator-dependent patients in intensive care units. It is useful in patients in whom tracheostomy is indicated, but refractory coagulopathy is a deterrent.

Use of the diaphragm to reinforce anastomosis of the intestines.

Use of a diaphragmatic flap to buttress and help secure persistent intestinal fistula is described. The potential for the use of muscle flaps in the management of recurrent intestinal fistula is presented.