Pneumoperitoneum does not potentiate the nephrotoxicity of aminoglycosides in rats

Renal Perfusion and Function during Pneumoperitoneum: A Systematic Review and Meta-Analysis of Animal Studies

Both preclinical and clinical studies indicate that raised intra-abdominal pressure (IAP) associated with pneumoperitoneum during laparoscopic surgical procedures can cause renal damage, the severity of which may be influenced by variables such as pressure level and duration. Several of these variables have been investigated in animal studies, but synthesis of all preclinical data has not been performed. This systematic review summarizes all available pre-clinical evidence on this topic, including an assessment of its quality and risk of bias. We performed meta-analysis to assess which aspects of the pneumoperitoneum determine the severity of its adverse effects. A systematic search in two databases identified 55 studies on the effect of pneumoperitoneum on renal function which met our inclusion criteria. There was high heterogeneity between the studies regarding study design, species, sex, pressure and duration of pneumoperitoneum, and type of gas used. Measures to reduce bias were poorly reported, leading to an unclear risk of bias in the majority of studies. Details on randomisation, blinding and a sample size calculation were not reported in ≥80% of the studies. Meta-analysis showed an overall increase in serum creatinine during pneumoperitoneum, and a decrease in urine output and renal blood flow. Subgroup analysis indicated that for serum creatinine, this effect differed between species. Subgroup analysis of pressure level indicated that urine output decreased as IAP level increased. No differences between types of gas were observed. Data were insufficient to reliably assess whether sex or IAP duration modulate the effect of pneumoperitoneum. Four studies assessing long-term effects indicated that serum creatinine normalized ≥24 hours after desufflation of pneumoperitoneum at 15mmHg. We conclude that harmful effects on renal function and perfusion during pneumoperitoneum appear to be robust, but evidence on long-term effects is very limited. The reliability and clinical relevance of these findings for healthy patients and patients at high risk of renal impairment remain uncertain. We emphasize the need for rigorous reporting of preclinical research methodology, which is of vital importance for clinical translation of preclinical data.

A função renal de ratos espontaneamente hipertensos submetidos ao pneumoperitônio

Objetivo: Estudar a função renal de ratos espontaneamente hipertensos submetidos ao pneumoperitônio com CO2. Métodos: Foram utilizados 60 ratos, sendo 30 Wistar SHR e 30 EPM-1 Wistar, com idade ao redor de quatro meses, com peso médio de 341g. A amostra foi distribuída em dois grupos, experimento (ratos hipertensos) e controle (ratos normotensos), de acordo com a linhagem, SHR e EPM-1 Wistar, respectivamente. Cada grupo foi redistribuído em dois subgrupos, com 15 animais cada, de acordo com a pressão de pneumoperitônio, 10 e 4mmHg. Os animais foram anestesiados e posicionados, dando início ao procedimento de cateterização da artéria femoral esquerda, que permitiu aferição da pressão arterial média e a coleta sanguínea durante todo o experimento. Após a anti-sepsia, procedeu-se à realização de incisão transversa de 5mm de comprimento na região central do abdome para introdução de trocarte de 2mm, por onde foi introduzida a agulha de Veress, permitindo a insuflação de CO2 até atingir a pressão estabelecida para cada grupo (4mmHg ou 10mmHg), que foi mantida durante uma hora, seguida por uma hora de desinsuflação. Ao término do período de desinsuflação todos os animais de todos os grupos, ainda sob efeito anestésico, foram submetidos à eutanásia por exanguinação, através do cateter arterial. As amostras de sangue foram coletadas em três fases: 1) após a cateterização, 2) após uma hora de pneumoperitônio, e 3) após uma hora de desinsuflação, sendo conduzidas ao laboratório para dosagens de uréia e creatinina. Resultados: Houve aumento da creatinina para o rato SHR durante pneumoperitônio com pressão de 10mmHg; já a uréia mostrou-se aumentada tanto para o SHR quanto para o Wistar, durante o pneumoperitônio com pressão de 10mmHg. Durante o pneumoperitônio com pressão de 4mmHg, a creatinina e a uréia mantiveram-se nos níveis basais. Conclusão: A função renal do SHR se altera de forma transitória, semelhante ao rato não-hipertenso quando submetido ao pneumoperitônio.

Minimizing ports to improve laparoscopic cholecystectomy

BACKGROUND

Minimizing the number and scope of ports used to perform laparoscopic cholecystectomy attempts to build on the improvements in postoperative pain control, rapid return to activity and work, patient satisfaction, and cosmetic result achieved by the laparoscopic method.

METHODS

We studied 141 patients in two sequential studies: the first a prospective randomized trial with 41 patients, and the second an examination of the more minimal procedure in 100 patients. In the randomized trial, patients underwent laparoscopic cholecystectomy with three ports: three 5-mm ports or two 10-mm ports and one 5-mm port. The 100 patients underwent the three 5-mm port procedure.

RESULTS

In the randomized trial, differences were not statistically significant. However, on the average, the group with three 5-mm ports required less medication over less time, had less postoperative pain, and took less time to return to activity than the second group with larger ports. A statistically significant difference was found in incisional pain between the smaller group (21 patients) with two 10-mm ports and one 5-mm port and the larger group (100 patients) with three 5-mm ports, whether the measure was overall incisional pain (p = 0.014) or a comparison based on specific ports (p = 0.001). The percentage of cases requiring port enlargement to remove the gallbladder was not significantly different between the groups. There were no conversions to an open procedure, no fourth trocars added, and no complications. No patient required overnight hospitalization.

CONCLUSIONS

Reducing the number and size of ports in laparoscopic cholecystectomy sustains or enhances the improvements initiated by performing laparoscopic rather than open cholecystectomy. In a comparison of microlaparoscopic procedures, patients undergoing the procedure with the shorter incisions experienced significantly less pain.