Benefits and harms of adhesion barriers for abdominal surgery: a systematic review and meta-analysis

Preoperative nomogram to predict risk of bowel injury during adhesiolysis

BACKGROUND

Inadvertent bowel injury during adhesiolysis is a major cause of increased morbidity and mortality following abdominal surgery. Identification of risk factors predicting this complication would guide preoperative counselling and surgical decision-making. The aim of this study was to identify predictive preoperative factors for inadvertent bowel injury occurring during adhesiolysis.

METHODS

All patients undergoing elective abdominal surgery between June 2008 and June 2010 were evaluated prospectively as part of the LAPAD study. Data on adhesiolysis and inadvertent organ injury were gathered by direct observation during operation. Univariable logistic regression was used to investigate factors that increased the risk of inadvertent bowel injury. Independent predictors of bowel injury were identified using multivariable logistic regression and used to create a clinical nomogram.

RESULTS

Of 715 patients eligible for analysis, 48 (6.7 per cent) had inadvertent bowel injuries. In 42 patients the defect was detected during operation and in nine at a later time (3 patients had both). Bowel resection was required for almost two-thirds of the enterotomies. The number of previous laparotomies, anatomical site of the operation, presence of bowel fistula and laparotomy via a pre-existing median scar were independent predictors of bowel injury. A clinical scoring system was constructed using a nomogram incorporating these risk factors; this had a predictive discrimination, measured as the area under the receiver operating characteristic curve, of 0.85.

CONCLUSION

A nomogram based on four independent factors predicted the risk of inadvertent bowel injury.

REGISTRATION NUMBER

NCT01236625 (http://www.clinicaltrials.gov).

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO₂ pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO₂, N₂O and O₂ seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.