Perspectives of bilateral thoracic sympathectomy for treatment of heart failure

Surgical neuromodulation therapies are still considered a last resort when standard therapies have failed for patients with progressive heart failure (HF). Although a number of experimental studies have provided robust evidence of its effectiveness, the lack of strong clinical evidence discourages practitioners. Thoracic unilateral sympathectomy has been extensively studied and has failed to show significant clinical improvement in HF patients. Most recently, bilateral sympathectomy effect was associated with a high degree of success in HF models, opening the perspective to be investigated in randomized controlled clinical trials. In addition, a series of clinical trials showed that bilateral sympathectomy was associated with a decreased risk of sudden death, which is an important outcome in patients with HF. These aspects indicates that bilateral sympathectomy could be an important alternative in the treatment of HF wherein pharmacological treatment barely reaches the target dose.

Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study

OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30 percent, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70 percent reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage.

Estudo dos efeitos da solução salina hipertônica e do Ringer lactato sobre a resposta da microcirculação mesentérica e a translocação bacteriana em modelo de obstrução intestinal e isquemia em ratos / Study of the effects of hypertonic saline and lactated Ringer´s solutions on mesenteric microcirculatory response and bacterial translocation in a rat model of intestinal obstruction and ischemia

INTRODUÇÃO: Estudos demonstram que a solução salina hipertônica melhora a hemodinâmica, a microcirculação e modula o sistema imune, atenuando a resposta inflamatória associada ao choque e trauma. Este estudo tem por objetivo avaliar e comparar os efeitos da solução salina hipertônica (NaCl, 7,5%) e do Ringer lactato seguido da ressecção de segmento do intestino necrosado no tratamento da obstrução intestinal e isquemia, através da análise da translocação bacteriana, da disfunção microcirculatória mesentérica, dos distúrbios hemodinâmicos e metabólicos e da disfunção orgânica. MÉTODOS: Ratos Wistar machos (250 300 g) anestesiados (pentobarbital sódico, 50 mg/kg, i.p.) foram submetidos à obstrução intestinal e isquemia (OI, ligadura ao nível do íleo terminal seguida de ligadura de ramos da artéria mesentérica correspondentes à irrigação de 7 10 cm do íleo). Duas horas após os animais foram randomizados em: OI sem tratamento (OI); OI tratado com Ringer lactato (RL, 4 mL/kg, i.v.); e OI tratado com solução salina hipertônica (SH 7,5%, 4 mL/kg, i.v.). Vinte e quatro horas após os procedimentos cirúrgicos iniciais, os ratos obstruídos (OI, RL e SH) foram submetidos à enterectomia. Ratos controles falso-operados (FO) foram submetidos à lapatotomia. Os seguintes parâmetros foram analisados: 1) cultura bacteriana (E. coli) em amostras de linfonodos mesentéricos, fígado, baço e sangue; 2) análise das interações leucócito-endotélio na microcirculação mesentérica por técnica de microscopia intravital; 3) expressão de moléculas de adesão endoteliais (P-selectina e ICAM-1) por imunohistoquímica; 4) quantificação das citocinas e quimiocinas CINC-1 e CINC-2 no soro por enzimaimunoensaio; 5) histologia intestinal; 6) bioquímica sérica; 7) gasometria, hematócrito, lactato, glicose e leucograma; 8) insulina e corticosterona e; 9) sobrevida. RESULTADOS: O tratamento com SH reduziu a bacteremia, a incidência de animais com amostras positivas para E. coli (57%) e a quantidade de...

BACKGROUND: It has been shown that hypertonic saline solution improve hemodynamics, the microcirculation, and modulate the immune system, attenuating the inflammatory response associated with shock and trauma. The present study aims to investigate and compare the effects of hypertonic saline solution (NaCl, 7.5%) and lactated Ringer´s solution in the treatment of intestinal obstruction and ischemia, analysing the bacterial translocation phenomenon, mesenteric microcirculatory dysfunctions, hemodynamic/metabolic disturbances, and organ dysfunction in a rat model of intestinal obstruction and ischemia (IO) followed by resection of the necrotic small bowel segment. METHODS: Anesthetized (pentobarbital 50 mg/kg, i.p.) male Wistar rats (250-300 g) were submitted to IO (ligature at the level of the terminal ileum, followed by ligation of mesenteric vessels that supply 7 10 cm of the ileal loop). Two hours thereafter animals were randomized into: IO without treatment; IO treated with lactated Ringer´s (LR, 4 ml/kg, i.v.) solution; IO treated with hypertonic saline (HS, 7.5%, 4 mL/kg, i.v.) solution. Twenty-four hours thereafter, IO rats (IO, LR, HS) were submitted to enterectomy. Control Sham-operated rats were submitted to laparotomy only. The following parameters were analysed: 1) bacterial cultures (E. coli) from mesenteric lymph nodes, liver, spleen, and blood samples; 2) analyses of leukocyte-endothelial interactions at the mesenteric microcirculation by intravital microscopy; 3) expression of endothelial adhesion molecules (P-selectin, ICAM-1) by immunohistochemistry; 4) quantification of serum cytokines and chemokines (CINC-1, CINC-2) by enzyme-linked immunosorbent assay; 5) intestinal histology; 6) serum biochemistry; 7) blood gases, hematocrit, lactate, glycemia, white blood cell counts; 8) serum insulin and corticosterone; 9) survival rate. RESULTS: Treatment with HS reduced the number of animals with positive samples for the presence of E. coli (57%)...

Mesenteric microcirculatory dysfunctions and translocation of indigenous bacteria in a rat model of strangulated small bowel obstruction

PRUPOSE: Bacterial translocation has been shown to occur in critically ill patients after extensive trauma, shock, sepsis, or thermal injury. The present study investigates mesenteric microcirculatory dysfunctions, the bacterial translocation phenomenon, and hemodynamic/metabolic disturbances in a rat model of intestinal obstruction and ischemia. METHODS: Anesthetized (pentobarbital 50 mg/kg, i.p.) male Wistar rats (250-350 g) were submitted to intestinal obstruction or laparotomy without intestinal obstruction (Sham) and were evaluated 24 hours later. Bacterial translocation was assessed by bacterial culture of the mesenteric lymph nodes (MLN), liver, spleen, and blood. Leukocyte-endothelial interactions in the mesenteric microcirculation were assessed by intravital microscopy, and P-selectin and intercellular adhesion molecule (ICAM)-1 expressions were quantified by immunohistochemistry. Hematocrit, blood gases, lactate, glucose, white blood cells, serum urea, creatinine, bilirubin, and hepatic enzymes were measured. RESULTS: About 86 percent of intestinal obstruction rats presented positive cultures for E. coli in samples of the mesenteric lymph nodes, liver, and spleen, and 57 percent had positive hemocultures. In comparison to the Sham rats, intestinal obstruction induced neutrophilia and increased the number of rolling (~2-fold), adherent (~5-fold), and migrated leukocytes (~11-fold); this increase was accompanied by an increased expression of P-selectin (~2-fold) and intercellular adhesion molecule-1 (~2-fold) in the mesenteric microcirculation. Intestinal obstruction rats exhibited decreased PaCO2, alkalosis, hyperlactatemia, and hyperglycemia, and increased blood potassium, hepatic enzyme activity, serum urea, creatinine, and bilirubin. A high mortality rate was observed after intestinal obstruction (83 percent at 72 h vs. 0 percent in Sham rats). CONCLUSION: Intestinal obstruction and ischemia in rats is a relevant model for ...