Influence of laparoscopy and laparotomy on gasometry, leukocytes and cytokines in a rat abdominal sepsis model

Advances in the diagnosis of non-occlusive mesenteric ischemia and challenges in intra-abdominal sepsis patients: a narrative review

Non-occlusive mesenteric ischemia (NOMI) is a type of acute mesenteric ischemia (AMI) with a high mortality rate mainly because of a delayed or misdiagnosis. Intra-abdominal sepsis is one of the risk factors for developing NOMI, and its presence makes early diagnosis much more difficult. An increase in routine abdominal surgeries carries a corresponding risk of abdominal infection, which is a complication that should not be overlooked. It is critical that physicians are aware of the possibility for intestinal necrosis in abdominal sepsis patients due to the poor survival rate of NOMI. This review aims to summarize advances in the diagnosis of NOMI, and focuses on the diagnostic challenges of mesenteric ischemia in patients with intra-abdominal sepsis.

STEM CELLS HEMATOPOIETIC NICHES AND INFLAMMATORY RESPONSE TO DIFFERENT SYNTHETIC PROSTHESIS IMPLANTED IN RAT WITH INCISIONAL HERNIAS

Background:

Extramedullary hematopoiesis depends on complex pathophysiological mechanisms linked to hematopoietic stem cells and the proteins considered mediators of the inflammation. The identification of hematopoietic cells outside bone marrow in the adult is an occurrence that can occasionally follows the inflammatory response, was considered a secondary occurrence, but current biomolecular studies have changed that concept.

Aim:

Describe the presence of clusters of precursor cells of platelets (megakaryocytes), and cells of the inflammatory response in the abdominal wall and spleen of rats with experimentally induced incisional hernias and repaired with different synthetic prostheses.

Methods:

Twenty-five rats with incisional hernias previously performed, were divided into groups of five animals each: Group 1, repair of the hernia defect without prosthetic implant; Group 2, repair with polypropylene prosthesis; Group 3, repair using polypropylene with low weight; Group 4, the use of polypropylene and polyglecaprone prosthesis; Group 5, of polypropylene and polyglactin prosthesis. All prostheses were cut in rhombus format with area 2,625 cm². The animals were reoperated after 10 days, the abdominal walls were removed with the viscera attached to them and the material was processed for histological study.

Results:

Megakaryocyte niches in the abdominal wall and spleen, occasionally removed together with the adhesions produced in animals with implantation of prostheses and significant inflammatory reaction.

Conclusion:

The intense inflammatory reaction due to the prostheses with polypropylene in their composition was disproportionate to the expected response, indicating that further studies should be accomplished including immunophenotyping evaluation and specific panels of monoclonal antibodies to better understand the findings.

Carbon dioxide‑pneumoperitoneum in rats reduces ischemia/reperfusion‑induced hepatic apoptosis and inflammatory responses by stimulating sensory neurons

Laparoscopic surgery induces a milder inflammatory response than open surgery, however, the precise mechanisms underlying this phenomenon remain to be elucidated. Our previous study demonstrated that stimulation of sensory neurons inhibited hepatic apoptosis and inflammatory responses in rats subjected to hepatic ischemia/reperfusion (I/R). Since carbon dioxide (CO2) has been demonstrated to stimulate sensory neurons, it was hypothesized that CO2‑pneumoperitoneum, as used in laparoscopic surgery, may attenuate inflammatory responses by stimulating sensory neurons. This hypothesis was examined using rats subjected to hepatic I/R. The rats were subjected to partial hepatic ischemia for 60 min followed by reperfusion. Abdominal insufflation with CO2 or air was performed for 30 min prior to hepatic I/R. Hepatic I/R‑induced hepatocellular apoptosis and expression of the neutrophil chemoattractant endothelial monocyte‑activated polypeptide‑II, were inhibited by CO2‑pneumoperitoneum, however, not by air‑pneumoperitoneum. Pretreatment with the transient receptor potential vanilloid 1 antagonist SB366791 reversed the protective effects of CO2‑pneumoperitoneum. The results from the present study demonstrated that CO2‑pneumoperitoneum attenuates hepatic apoptosis and inflammatory responses in rats subjected to hepatic I/R, possibly by stimulating sensory neurons. These findings suggested that CO2‑pneumoperitoneum contributed to the attenuated inflammatory response observed following laparoscopic surgery.

A study of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) serum levels in rats subjected to fecal peritonitis and treated with intraperitoneal ropivacaine

PURPOSE

The objective of this study was to assess the cytokine serum levels of IL-6 and TNF-α in rats subjected to fecal peritonitis and treated with peritoneal lavage with 0.2% ropivacaine by peritoneal lavage.

METHODS

We subjected 16 Wistar rats to laparotomy 6 hours after the induction of fecal peritonitis with autogenous stool and subsequently divided the rats randomly into 4 groups: I-control, no treatment; II- drying of the abdominal cavity; III- lavage of the abdominal cavity with 3 mL of 0.9% normal saline and drying; IV- lavage of the abdominal cavity with 3 mL of 0.2% ropivacaine and drying. Six hours following the laparotomy, the animals underwent cardiac puncture, and 1 mL of blood was collected for cytokine assessment before the animals were euthanized.

RESULTS

The lavage with ropivacaine resulted in smaller TNF-α levels compared with those observed in the other treatment groups (p <0.05). Regarding IL-6, the ropivacaine group showed lower cytokine levels than those observed in groups I and II, but there was no significant difference (p> 0.05) between groups III and IV.

CONCLUSION

Peritoneal lavage with 0.2% ropivacaine was shown to reduce plasma levels of IL-6 and TNF-α in the treatment of fecal peritonitis in rats.

Peritoneal inflammatory response of natural orifice translumenal endoscopic surgery (NOTES) versus laparoscopy with carbon dioxide and air pneumoperitoneum

BACKGROUND

The immunologic and physiologic effects of natural orifice translumenal endoscopic surgery (NOTES) versus traditional surgical approaches are poorly understood. Previous investigations have shown that NOTES and laparoscopy share similar inflammatory cytokine profiles except for a possible late-phase tissue necrosis factor-alpha (TNF-alpha) depression with NOTES. The local peritoneal reaction and immunomodulatory influence of pneumoperitoneum agents in NOTES also are not known and may play an important role in altering the physiologic insult induced by NOTES.

METHODS

In this study, 51 animals were divided into four study groups, which respectively underwent abdominal exploration via transgastric NOTES using room air (AIR) or carbon dioxide (CO(2)) or via laparoscopy (LX) using AIR or CO(2) for pneumoperitoneum. Laparotomy and sham surgeries were additionally performed as control conditions. Measurements of TNF-alpha, interleukin-1beta (IL-1beta), and IL-6 were performed for peritoneal fluid collected after 0, 2, 4, and 6 h and on postoperative days (PODs) 1, 2, and 7.

RESULTS

Of the 45 animals assessed, 6 were excluded because of technical operative complications. The findings showed that LX-CO(2) generated the most pronounced response with all three inflammatory markers. However, no significant differences were detected between LX-CO(2) and either NOTES group at these peak points. No differences were encountered between NOTES-CO(2) and NOTES-AIR. Subgroup comparisons showed significantly higher levels of TNF-alpha and IL-6 with NOTES-CO(2) than with LX-AIR on POD 1 (p = 0.022) and POD 2 (p = 0.002). The LX-CO(2) subgroup had significantly higher levels of TNF-alpha than the LX-AIR subgroup at 4 h (p = 0.013) and on POD 1 (p = 0.021). No late-phase TNF-alpha depression occurred in the NOTES animals.

CONCLUSION

The local inflammatory reaction to NOTES was similar to that with traditional laparoscopy, and the previously described late-phase systemic TNF-alpha depression in serum was not reproduced. At the peritoneal level, NOTES is no more physiologically stressful than laparoscopy. Furthermore, regardless of which gas was used, the role of the pneumoperitoneum agent did not affect the cytokine profile after NOTES, suggesting that air pneumoperitoneum is adequate for NOTES.

Comparison of prophylactic and therapeutic use of short-chain fatty acid enemas in diversion colitis: a study in Wistar rats

OBJECTIVES

To study the effect of short-chain fatty-acids on atrophy and inflammation of excluded colonic segments before and after the development of diversion colitis.

INTRODUCTION

Diversion colitis is a chronic inflammatory process affecting the dysfunctional colon, possibly evolving with mucous and blood discharge. The most favored hypotheses to explain its development is short-chain fatty-acid deficiency in the colon lumen.

METHODS

Wistar rats were submitted to colostomy with distal colon exclusion. Two control groups (A1 and B1) received rectally administered physiological saline, whereas two experimental groups (A2 and B2) received rectally administered short-chain fatty-acids. The A groups were prophylactically treated (5th to 40th days postoperatively), whereas the B groups were therapeutically treated (after post-operative day 40). The mucosal thickness of the excluded colon was measured histologically. The inflammatory reaction of the mucosal lamina propria and the lymphoid tissue response were quantified through established scores.

RESULTS

There was a significant thickness recovery of the colonic mucosa in group B2 animals (p = 0.0001), which also exhibited a significant reduction in the number of eosinophilic polymorphonuclear cells in the lamina propria (p = 0.0126) and in the intestinal lumen (p = 0.0256). Group A2 showed no mucosal thickness recovery and significant increases in the numbers of lymphocytes (p = 0.0006) and eosinophilic polymorphonuclear cells in the lamina propria of the mucosa (p = 0.0022).

CONCLUSION

Therapeutic use of short-chain fatty-acids significantly reduced eosinophilic polymorphonuclear cell numbers in the intestinal wall and in the colonic lumen; it also reversed the atrophy of the colonic mucosa. Prophylactic use did not impede the development of mucosal atrophy.

Analysis of the bactericidal effect of ozone pneumoperitoneum

PURPOSE

To assess the bactericidal action of ozone pneumoperitonium, and to compare the results with CO2.

METHODS

It was used 36 Wistar rats. The animals, under anesthesia, were inoculated with 2ml of E. coli ATCC at a concentration of 10(10)UFC, and 1ml of BaSO4, into the peritoneal cavity. They were divided into three groups: Group 1, CO2 pneumoperitoneum was performed for 15 minutes; Group 2, ozone pneumoperitoneum was performed for 5 minutes at a concentration of 42microg/ml, and Group 3, ozone pneumoperitoneum was performed for 5 minutes at a concentration of 62microg/ml. Six animals from each group were sacrificed after the experiment, and the remaining 6 observed for 24 hours. Material was collected from the cavity of all animals for microbiological study.

RESULTS

Ozone presented a greater bactericidal effect than CO2 in those animals sacrificed immediately after pneumoperitoneum. In the animals studied 24 hours after pneumoperitoneum evidenced no difference in bactericidal effect between the two gases. Moreover, no difference in mortality was observed.

CONCLUSION

Ozone has a more potent bactericidal effect than carbon dioxide gas, although this did not influence survival of the animals.

Physiological effects of a novel immune stimulator drug, (1,4)-α-D-glucan, in rats

The (1,4)-α-D-glucan (α-D-glucan), derived from medicinal plant, Tinospora cordifolia, activates human lymphocytes with downstream synthesis of the pro- and anti-inflammatory cytokines, in vitro. We investigated physiological and immunological effects of a low and a high dose of α-D-glucan (0.5 and 10 mg/kg), in vivo, testing the hypothesis that intravenous administration of α-D-glucan does not affect haemodynamic, respiratory, haematological, and immune responses in normal rats. Male rats (300-400 g) were anaesthetized, tracheostomized, and catheterized in one femoral artery and vein. The mean arterial blood pressure and heart rate were continuously recorded. The baselines for gas exchange, differential blood cell count, and plasma concentration of TNF-α, IL-1β, IL-4, IL-6, and IFN-γ were determined. Rats were then randomly assigned to controls (n = 7), a low dose (0.5 mg/kg; n = 10), and a high dose (10 mg/kg; n = 7) of α-D-glucan for a six 6 hr study period. Gas exchange, differential cell count, plasma concentration of TNF-α, IL-1β, IL-4, IL-6, and IFN-γ, and mean arterial blood pressure values remained within physiological range. Intravenous administration of 10 mg/kg α-D-glucan created tachycardia, associated with hyperventilation, and significant reductions in the blood haemoglobin and haematocrit concentrations. We suggest that these in vivo effects of α-D-glucan should be considered for future clinical and/or experimental trials.

Effects of peritoneal lavage with lidocaine on survival of rats with fecal peritonitis

PURPOSE

To study the effects of peritoneal lavage with a 2% lidocaine solution, on the survival of the rats submitted to peritonitis caused by their own feces.

METHODS

Forty-eight Wistar rats, weighting between 300 g and 330 g (mean, 311,45 +/-9,67 g), were submitted to laparotomy 6 hours following induction of fecal peritonitis. Animals were randomly divided into four groups of 12 each as follows: 1- Control, no therapy; 2- Drying of the abdominal cavity; 3- Peritoneal lavage with saline and drying; 4- Peritoneal lavage with a 2% lidocaine solution and drying. Animals that died were submitted to necropsy and the time of their death recorded; survivors were killed on the post-operation 11th day and necropsied.

RESULTS

Death occurred within 52 h in all animals of group 1; within 126 h in 100% of those of group 2; within 50 h in 50% of those of group 3. All animals of group 4 survived. Survival on the 11 th day was higher in groups 3 and 4 than in groups 1 and 2 (p<0.001), and higher in group 4 than in group 3 (p<0.01).

CONCLUSION

Peritoneal lavage with a 2% lidocaine saline solution without adrenaline, prevented the mortality of all animals with fecal peritonitis.

Late phase TNF-alpha depression in natural orifice translumenal endoscopic surgery (NOTES) peritoneoscopy

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) allows access to the peritoneal cavity without skin incisions. Contamination of the peritoneal cavity by enteric contents may render NOTES more physiologically and immunologically invasive than previously thought. Measurement of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) is a validated method to quantify surgical stress. The physiologic and immunologic impact of NOTES is unknown.

METHODS

A total of 37 swine underwent abdominal exploration via transgastric NOTES peritoneoscopy, laparoscopy (LX), laparotomy (OPEN), or sham surgery (CONTROL) and were allowed to survive. TNF-alpha, IL-1beta, and IL-6 plasma levels were determined at the start and completion of surgery, and at 1 hour, 2 days, and 14 days postoperatively.

RESULTS

At surgical completion, OPEN animals demonstrated higher TNF-alpha levels than all groups. TNF-alpha levels were similar for all groups at 1 hour and 2 days. NOTES animals had significantly reduced plasma levels of TNF-alpha than all other groups on postoperative days 7 and 14. Controlling for baseline cytokine variability, analysis was repeated using normalized data, which confirmed significantly reduced TNF-alpha levels for NOTES compared with all groups at 14 days. Subset analysis excluding LX and OPEN complications revealed lower NOTES TNF-alpha levels at 7 and 14 days compared with all groups. IL-1beta and IL-6 levels were undetectable in 66.8% and 70.5% of samples, respectively, without significant trends.

CONCLUSIONS

Diagnostic NOTES peritoneoscopy demonstrated similar levels of systemic proinflammatory cytokine TNF-alpha compared with diagnostic laparoscopy and exploratory laparotomy in the immediate postoperative period despite gross intraperitoneal contamination. None of the surgical groups, however, produced a measurable, consistent trend in IL-1beta or IL-6. Consistently reduced levels of TNF-alpha in NOTES animals in the late postoperative period indicates an immunomodulatory effect of the NOTES surgical technique not present in laparoscopy or laparotomy.

Gasometria arterial e inflamação pulmonar de ratos com diferentes tempos de sepse abdominal

RACIONAL: Sepse é a principal causa de morbi-mortalidade nas vítimas de trauma e em pacientes cirúrgico e apesar de toda tecnologia e terapêutica disponível não há diminuição nestas estatísticas. OBJETIVOS: Avaliar as repercussões ácido-básicas e o grau de injúria pulmonar decorrentes de sepse abdominal em ratos após seis e 24 horas de peritonite fecal através da ligadura e punção do ceco. MÉTODOS: Foram utilizados 40 ratos Wistar, machos, adultos. A amostra foi dividida aleatoriamente em quatro grupos: grupo A (sham/6 h - n=5) submetidos à laparotomia mediana infra-umbilical sem nenhuma outra intervenção; grupo B (sham/24h - n=5) submetidos à laparotomia mediana infra-umbilical sem nenhuma outra intervenção; grupo C (LPC/6 h - n=15) submetidos à ligadura e punção do ceco e grupo D (LPC/24h - n=15) submetidos à ligadura e punção do ceco. Após seis ou 24 horas, conforme o grupo em estudo, os animais foram novamente anestesiados e submetidos as seguintes análises: observação clínica de sinais de sepse, laparotomia através do mesmo acesso anterior e realização de cultura do líquido peritoneal e punção cardíaca para obtenção de amostra sangüínea suficiente para gasometria arterial, hematócrito e leucometria. Procedeu-se eutanásia e os pulmões retirados para análise de edema pulmonar e o infiltrado inflamatório. RESULTADOS: Ocorreram quatro óbitos no grupo D. Verificou-se, em todos os grupos, a presença de acidose mista. Comparando os grupos experimento 6h versus controle 6h foram encontradas duas variáveis significativas - HCO3 (p=0,0015) e BE (p=0,0015) -, demonstrando acidose metabólica mais grave no grupo experimento. Nos grupos controle também se confirmou acidose mista, devido às alterações das variáveis HCO3 (p=0,0079), PO2 (p=0,0079) e SO2 (p=0,0079). A correlação entre o grau de comprometimento pulmonar e o estado metabólico confirma a existência de resposta inflamatória sistêmica evidenciada por aumento de neutrófilos e hemorragia alveolar difusa nos pulmões do rato séptico. CONCLUSÃO: O modelo de LPC foi método eficaz para indução de sepse. A laparotomia e a manipulação de alças intestinais são fatores desencadeantes de acidose mista em ratos, comprovado pelos resultados da gasometria, que demonstrou ser método confiável na detecção de alterações no metabolismo ácido-básico dos ratos estudados.