Experimental study of starch-induced intraperitoneal adhesions

Analysis of adhesion formation of a new elastic thermoplastic polyurethane (TPU) mesh in comparison to polypropylene (PP) meshes in IPOM position

BACKGROUND

Postsurgical adhesions severely affect the patients' quality of life causing various complications like bowel obstruction or chronic pain. Especially the implantation of alloplastic prostheses in IPOM position for hernia repair carries a high risk of adhesion formation due to the close contact between mesh and viscera. The extent of adhesions mainly depends on the type and textile characteristics of the implanted mesh. The aim of this study was to examine the degree of adhesion formation of a newly developed, elastic thermoplastic polyurethane (TPU) mesh in comparison to polypropylene (PP) meshes in IPOM position in a rabbit model.

METHODS

Sixteen female chinchilla rabbits were laparoscopically operated. Two different meshes were placed to the left and the right lower abdominal wall in IPOM position in each rabbit. After 7 or 21 days, midline laparotomy was performed, the degree of adhesion formation was examined by the Diamond score and mesh elongation was measured under a force of 3N. Finally, the abdominal walls were explanted for immunohistochemical and histopathological investigations.

RESULTS

TPU meshes showed significantly lower Diamond scores than PP meshes. After explantation, mesh elongation of the TPU mesh was significantly larger than expansion of PP under a force of 3N. Thus, the TPU mesh preserved its elastic properties after 7 and 21 days. The amount of CD68 positive, Ki67 positive and apoptotic cells within the granuloma around the fibers did not show significant differences between the study groups.

CONCLUSIONS

The newly developed TPU mesh seems to reduce peritoneal adhesion formation in IPOM position in a rabbit model compared to PP meshes after 7 and 21 days. Immunohistochemistry did not reveal differences in biocompatibility of the two meshes used.

Effect of composite resin contamination with powdered and unpowdered latex gloves on its shear bond strength to bovine dentin

The aim of the present study was to evaluate the effect of composite resin contamination with powdered and unpowdered latex gloves on the shear bond strength of etch-and-rinse and two-step self-etch adhesive systems. Standard flat dentin surfaces were prepared on the facial aspect of 120 bovine incisors and randomly assigned into two (n=60) groups: group 1: Single Bond (SB), group 2: Clearfil SE Bond (CSE). Furthermore, each group was randomly subdivided into three (n=20) based on the type of composite contamination (without contamination, contamination with powdered latex gloves, and contamination with unpowdered latex gloves). The adhesives were applied and resin composite bonded to the dentin. After thermocycling, the specimens were subjected to a shear bond strength test. Two-way analysis of variance (ANOVA) and a post hoc Bonferroni test were used for statistical analysis. One-way ANOVA was used to compare shear bond strength values in each group. Statistical significance was set at p < 0.02. Two-way ANOVA showed that the shear bond strength was significantly influenced by the type of composite surface contamination (p=0.001). In the SB group there were no significant differences between different surface treatments (p=0.08). In the CSE group a significant difference was observed between the subgroup without contamination and the subgroup with powdered latex glove contamination (p=0.01); however, no significant differences were observed between the other subgroups.

Glove powder reduction and alternative approaches

This article addresses the role of glove powder in facilitating allergic reactions to natural rubber latex (NRL) and to the chemical additives in synthetic and NRL gloves as well as its role in eliciting postsurgical complications. Various dusting powders have been used historically to prevent gloves from sticking to each other and to facilitate donning. All have manifested adverse consequences for health care professionals and patients. Manufacturing methods for powder reduction and elimination are presented. The recently developed ASTM methods for the quantitation of powder on powder-free and powdered gloves are reviewed along with the new ASTM maximum powder limits for all medical gloves. Caution must be exercised when methods of protein and powder reduction are implemented to minimize the possibility of creating other adverse consequences.

Glove powder promotes adhesion formation and facilitates tumour cell adhesion and growth

BACKGROUND

The presence of foreign material in the abdominal cavity irritates the peritoneal surface, leading to an inflammatory response. This defensive mechanism can provoke adhesion formation. The same peritoneal defence cascade is thought to play a role in the process of intra-abdominal tumour recurrence. The aim of this study was to evaluate whether glove powder produced peritoneal adhesions in a rat adhesion model and whether it promoted intra-abdominal tumour recurrence in a rat tumour cell adhesion and growth model.

METHODS

A reproducible model that allowed semiquantitative scoring of adhesion formation or tumour load was used in three different groups of rats. One group was treated by intra-abdominal application of powder obtained from starch-powdered gloves, one by application of pure starch and in one group no powder was used.

RESULTS

Application of glove powder or pure starch on minimally and severely traumatized peritoneum gave rise to significantly greater adhesion formation and intra-abdominal tumour load than peritoneal trauma alone (both P < 0.001).

CONCLUSION

Starch-induced peritoneal trauma leads not only to more adhesion formation but also to increased adhesion and growth of tumour cells. Since good powder-free alternatives are available there is no longer any justification for the use of powdered gloves during intra-abdominal surgery.

Are ophthalmic surgeons aware that starch powdered surgical gloves are a risk factor in ocular surgery?

PURPOSE

To assess the level of awareness among UK ophthalmic surgeons of the potential risks from starch powdered surgical gloves during ophthalmic surgery and to show by electron microscopy that starch granule contamination can occur during ophthalmic surgery.

SETTING

A sample (N = 46) of UK ophthalmologists from the North of England, UK.

METHODS

Type of glove usage and awareness of the possible risks from starch powdered surgical gloves were assessed by means of a questionnaire sent to ophthalmic surgeons in the North of England. The surface of a polymethylmethacrylate (PMMA) intraocular lens (IOL) handled with a starch powdered surgical glove was examined by electron microscopy for evidence of starch contamination.

RESULTS

Of the sampled ophthalmic surgeons (46), 89.1% considered it important to use starch free surgical gloves and the 84.8% already did so. Starch granule contamination was seen by electron microscopy on the surface of a PMMA IOL which had been handled with starch powdered surgical gloves.

CONCLUSIONS

Although there has been sporadic attention in the ophthalmic literature to the risks associated with starch powdered surgical gloves in ophthalmology, up to 15% of UK ophthalmic surgeons may still be using starch powdered gloves. The authors show that starch powder contamination of ophthalmic materials can actually occur and remind ophthalmologists that this has been reported in the literature as a possible cause of sterile intra and extraocular inflammation.

The fate of intraperitoneally retained gallstones with different morphologic and microbiologic characteristics: an experimental study

Management of intraperitoneally retained gallstones after laparoscopic cholecystectomy (LC) is controversial, as their natural course is not known. This study was undertaken to assess the probable effects of stone morphology and clinically obvious infection on the outcome of retained gallstones in a mouse model. Forty albino mice were divided into four groups. Group I served as the control group (simple laparotomy, n = 10). Groups II, III, and IV (n = 10 in each group) were study groups. "Intact-sterile-cholesterol" (group II), "crushed-sterile-cholesterol" (group III), and "intact" (n = 5) [group IVa] and "crushed" (n = 5) [group IVb] "infected-cholesterol" gallstones aseptically retrieved from three different human patients were implanted to the peritoneal cavity of the animals. Group IV animals were implanted with stones retrieved from an acutely inflamed gallbladder with proven infection. Animals were sacrificed 6 and 12 weeks after the operations. Cultures and tissue samples were obtained. No animal was lost, no microscopic or macroscopic abnormality was observed in groups I and II, and cultures remained negative. In group III, adhesions surrounding the fragmented stones were evident at the 12th week, and no mortality was encountered. The histopathology revealed a fibroblastic reaction, and cultures remained negative in group III. In group IV, three animals from group IVb and one animal from group IVa died because of intra-abdominal sepsis before their sacrifice. All remaining mice showed severe adhesions with localized abscesses at the 12th week. In conclusion, intraperitoneally retained cholesterol gallstones remain inert and do not cause serious peritoneal reaction unless they are crushed into fragments or are from an acutely inflamed gallbladder. It is for this group of patients that laparotomy for total stone clearance is probably not justifiable. Better stone retrieval techniques or even laparotomy may be worthwhile considering in patients with crushed and particularly infected retained stones.

Foreign material in postoperative adhesions

OBJECTIVE

The authors determined the prevalence of foreign body granulomas in intra-abdominal adhesions in patients with a history of abdominal surgery.

PATIENTS AND METHODS

In a cross-sectional, multicenter, multinational study, adult patients with a history of one or more previous abdominal operations and scheduled for laparotomy between 1991 and 1993 were examined during surgery. Patients in whom adhesions were present were selected for study. Quantity, distribution, and quality of adhesions were scored, and adhesion samples were taken for histologic examination.

RESULTS

In 448 studied patients, the adhesions were most frequently attached to the omentum (68%) and the small bowel (67%). The amount of adhesions was significantly smaller in patients with a history of only one minor operation or one major operation, compared with those with multiple laparotomies (p < 0.001). Significantly more adhesions were found in patients with a history of adhesions at previous laparotomy (p < 0.001), with presence of abdominal abscess, hematoma, and intestinal leakage as complications after former surgery (p = 0.01, p = 0.002, and p < 0.001, respectively), and with a history of an unoperated inflammatory process (p = 0.04). Granulomas were found in 26% of all patients. Suture granulomas were found in 25% of the patients. Starch granulomas were present in 5% of the operated patients whose surgeons wore starch-containing gloves. When suture granulomas were present, the median interval between the present and the most recent previous laparotomy was 13 months. When suture granulomas were absent, this interval was significantly longer--i.e., 30 months (p = 0.002). The percentage of patients with suture granulomas decreased gradually from 37% if the previous laparotomy had occurred up to 6 months before the present operation, to 18% if the previous laparotomy had occurred more than 2 years ago (p < 0.001).

CONCLUSIONS

The number of adhesions found at laparotomy was significantly larger in patients with a history of multiple laparotomies, unoperated intra-abdominal inflammatory disease, and previous postoperative intra-abdominal complications, and when adhesions were already present at previous laparotomy. In recent adhesions, suture granulomas occurred in a large percentage. This suggests that the intra-abdominal presence of foreign material is an important cause of adhesion formation. Therefore intra-abdominal contamination with foreign material should be minimized.

Evaluating the effect of glove coating on the shear bond strength of porcelain laminate veneers

Gloves have become a standard tool in dentistry due to infection control concerns. But the starch powder with which many of these gloves are coated may contaminate surfaces on contact, creating potential problems during adhesive procedures such as the placement of porcelain veneers. The authors studied the powder's effect on the strength of the shear bond of etched porcelain to etched human tooth enamel and compared it to the effect of a powder-free polymer glove coating. While the starch coating led to a statistically significant decrease in shear bond strength, the powder-free coating produced no significant decrease in strength.

Fibrin sealant in laparoscopic adhesion prevention in the rabbit uterine horn model

OBJECTIVE

To assess the effects of fibrin sealant on adhesions after laparoscopic surgery.

DESIGN

Standardized surgical trauma was induced in 60 female rabbits. The animals were randomized in three groups for different adhesion prevention treatment.

SETTING

University research laboratory.

INTERVENTIONS

After standardized trauma was induced, group 1 (n = 20) received no treatment, group 2 animals (n = 20) were injected in the abdominal cavity with 60 mL of Ringer's lactate, and human fibrin sealant was applied on the surgical lesions under laparoscopic vision in group 3 (n = 20).

MAIN OUTCOME MEASURES

Five weeks after laparoscopy, a laparotomy was performed, and the adhesions were scored.

RESULTS

Fourteen of 20 rabbits in the control group (70%) presented postoperative adhesions, 11 of 20 (55%) in the Ringer's group, and 5 of 20 (25%) in the fibrin sealant group. High-score adhesions were seen in 15% of cases in control and Ringer's group and in 5% of cases in the fibrin sealant group.

CONCLUSIONS

When used during laparoscopic surgery, fibrin sealant has a preventive effect on de novo postsurgical adhesions. To assess the efficacy in reproductive surgery, a trial on recurrent postsurgical adhesions is required.

The need to retrieve the dropped stone during laparoscopic cholecystectomy

The effect of bile and gallstones on the peritoneal cavity was evaluated in an experimental animal study. Ninety male Sprague-Dawley rats were randomly allocated to one of six groups (n = 15). Groups 1 to 3 received an intraperitoneal injection (2 mL) of saline, sterile bile, and infected bile, respectively. Groups 4 to 6 underwent a lower midline abdominal incision (3 to 5 mm). In groups 4 and 5, a single gallstone (< 3 mm diameter) was placed in the right upper quadrant and, after closure of the wound, the animals were injected with sterile bile and infected bile, respectively. Group 6 animals underwent laparotomy alone, followed by injection of sterile saline (2 mm). All animals were killed at 4 weeks and the peritoneal cavity was carefully examined. No intra-abdominal lesions were noted in groups 1 to 3. Adhesions were noted in 11 (73%) and 10 (67%) animals of groups 4 and 5, respectively. Two intra-abdominal abscesses were noted in group 4 animals. No intra-abdominal lesions were noted in any group 6 animals. This study suggests that bile in combination with gallstones in the peritoneal cavity is associated with an increased risk of intra-abdominal adhesion formation and possible abscess formation, and that every attempt should be made to retrieve stones lost during cholecystectomy.

Radiology of starch granulomatous peritonitis

Starch granulomatous peritonitis (SGP) is a rare complication of abdominal surgery that results, in a susceptible individual, from contamination of the peritoneal cavity with starch particles from the surgeon's gloves. It is important to make the diagnosis of SGP without recourse to re-operation as the optimal treatment is non-surgical. A case of SGP that was confirmed only after re-operation and resection of the involved tissues is reported. The first description of an abdominal computed tomography scan in this condition is presented, the significance of which was only recognized postoperatively.