Characteristics of different mesh types for abdominal wall repair in an experimental model of peritonitis

BACKGROUND

The use of synthetic mesh to repair a potentially contaminated incisional hernia may lead to higher failure rates. A biological mesh might be considered, but little is known about long-term results. Both biological and synthetic meshes were investigated in an experimental model of peritonitis to assess their characteristics in vivo.

METHODS

Male Wistar rats were randomized into five groups and peritonitis was induced. A mesh was implanted after 24 h. Five meshes were investigated: Permacol™ (cross-linked collagen), Strattice™ (non-cross-linked collagen), XCM Biologic^® (non-cross-linked collagen), Omyra^® Mesh (condensed polytetrafluoroethylene) and Parietene™ (polypropylene). The rats were killed after either 30, 90 or 180 days. Incorporation and shrinkage of the mesh, adhesion coverage, strength of adhesions and histology were analysed.

RESULTS

Of 135 rats randomized, 18 died from peritonitis. Some 180 days after implantation, both XCM Biologic^® and Permacol™ had significantly better incorporation than Strattice™ (P = 0·003 and P = 0·009 respectively). Strattice™ had significantly fewer adhesions than XCM Biologic^® (P = 0·001) and Permacol™ (P = 0·020). Thirty days after implantation, Permacol™ had significantly stronger adhesions than Strattice™ (P < 0·001). Shrinkage was most prominent in XCM Biologic^® , but no significant difference was found compared with the other meshes. Histological analysis revealed marked differences in foreign body response among all meshes.

CONCLUSION

This experimental study suggested that XCM Biologic^® was superior in terms of incorporation, macroscopic mesh infection, and histological parameters such as collagen deposition and neovascularization. There must be sufficient overlap of mesh during placement, as XCM Biologic^® showed a high rate of shrinkage. Surgical relevance The use of synthetic mesh to repair a potentially contaminated incisional hernia is not supported unequivocally, and may lead to a higher failure rate. A biological mesh might be considered as an alternative. There are few long-term studies, as these meshes are expensive and rarely used. This study evaluated the use of biological mesh in a contaminated environment, and investigated whether there is an ideal mesh. A new non-cross-linked biological mesh (XCM Biologic^® ) was evaluated in this experiment. The new non-cross-linked biological mesh XCM Biologic^® performed best and may be useful in patients with a potentially contaminated incisional hernia.

Cost analysis of laparoscopic lavage compared with sigmoid resection for perforated diverticulitis in the Ladies trial

Background

Laparoscopic peritoneal lavage is an alternative to sigmoid resection in selected patients presenting with purulent peritonitis from perforated diverticulitis. Although recent trials have lacked superiority for lavage in terms of morbidity, mortality was not compromised, and beneficial secondary outcomes were shown. These included shorter duration of surgery, less stoma formation and less surgical reintervention (including stoma reversal) for laparoscopic lavage versus sigmoid resection respectively. The cost analysis of laparoscopic lavage for perforated diverticulitis in the Ladies RCT was assessed in the present study.

Methods

This study involved an economic evaluation of the randomized LOLA (LaparOscopic LAvage) arm of the Ladies trial (comparing laparoscopic lavage with sigmoid resection in patients with purulent peritonitis due to perforated diverticulitis). The actual resource use per individual patient was documented prospectively and analysed (according to intention‐to‐treat) for up to 1 year after randomization.

Results

Eighty‐eight patients were randomized to either laparoscopic lavage (46) or sigmoid resection (42). The total medical costs for lavage were lower (mean difference € − 3512, 95 per cent bias‐corrected and accelerated c.i. −16 020 to 8149). Surgical reintervention increased costs in the lavage group, whereas stoma reversal increased costs in the sigmoid resection group. Differences in favour of laparoscopy were robust when costs were varied by ±20 per cent in a sensitivity analysis (mean cost difference € − 2509 to −4438).

Conclusion

Laparoscopic lavage for perforated diverticulitis is more cost‐effective than sigmoid resection.

Further evidence of lavage superiority

Hyperbaric oxygen therapy improves colorectal anastomotic healing

PURPOSE

Hyperbaric oxygen treatment (HBOT) has been found to improve the healing of poorly oxygenated tissues. This study aimed to investigate the influence of HBOT on the healing in ischemic colorectal anastomosis.

METHODS

Forty Wistar rats were randomly divided into a treatment group that received HBOT for 10 consecutive days (7 days before and 3 days after surgery), or in a control group, which did not receive the therapy. Colectomy with an ischemic anastomosis was performed in all rats. In each group, the rats were followed for 3 or 7 days after surgery to determine the influence of HBOT on anastomotic healing.

RESULTS

Five rats from each group died during follow-up. No anastomotic dehiscence was seen in the HBOT group, compared to 37.5 % and 28.6 % dehiscence in the control group on postoperative day (POD) 3 and 7, respectively. The HBOT group had a significantly higher bursting pressure (130.9 ± 17.0 mmHg) than the control group (88.4 ± 46.7 mmHg; p = 0.03) on POD 3. On POD 3 and POD 7, the adhesion severity was significantly higher in the control groups than in the HBOT groups (p < 0.005). Kidney function (creatinine level) of the HBOT group was significantly better than of the control group on POD 7 (p = 0.001). Interestingly, a significantly higher number of CD206+ cells (marker for type 2 macrophages) was observed in the HBOT group at the anastomotic area on POD 3.

CONCLUSION

Hyperbaric oxygen enhanced the healing of ischemic anastomoses in rats and improved the postoperative kidney function.

Systematic review of evidence and consensus on diverticulitis: an analysis of national and international guidelines

AIM

The study aimed to analyse the currently available national and international guidelines for areas of consensus and contrasting recommendations in the treatment of diverticulitis and thereby to design questions for future research.

METHOD

MEDLINE, EMBASE and PubMed were systematically searched for guidelines on diverticular disease and diverticulitis. Inclusion was confined to papers in English and those < 10 years old. The included topics were classified as consensus or controversy between guidelines, and the highest level of evidence was scored as sufficient (Oxford Centre of Evidence-Based Medicine Level of Evidence of 3a or higher) or insufficient.

RESULTS

Six guidelines were included and all topics with recommendations were compared. Overall, in 13 topics consensus was reached and 10 topics were regarded as controversial. In five topics, consensus was reached without sufficient evidence and in three topics there was no evidence and no consensus. Clinical staging, the need for intraluminal imaging, dietary restriction, duration of antibiotic treatment, the protocol for abscess treatment, the need for elective surgery in subgroups of patients, the need for surgery after abscess treatment and the level of the proximal resection margin all lack consensus or evidence.

CONCLUSION

Evidence on the diagnosis and treatment of diverticular disease and diverticulitis ranged from nonexistent to strong, regardless of consensus. The most relevant research questions were identified and proposed as topics for future research.