Biofilms and effective porosity of hernia mesh: are they silent assassins?

PURPOSE: The purpose of this paper is to communicate two new concepts with the potential to cause major morbidity in hernia repair, effective porosity and biofilm. These 2 concepts are interrelated and have the potential to result in mesh-related complications. Effective porosity is a term well described in the textile industry. It is best defined as the changes to pore morphology after implantation of mesh in situ. It is heavily dependent on mesh construct and repair technique and has the potential to impact hernia repair by reducing mesh tissue integration and promoting fibrosis. Bacterial biofilm is a well-described condition affecting prosthesis in breast and join replacement surgery with catastrophic consequences. There is a paucity of information on bacterial biofilm in mesh hernia repair. We speculate that bacterial biofilm has the potential to reduce the effective porosity of mesh, resulting in non-suppurative mesh-related complications as well as the potential for late suppurative infections. We describe the aetiology, pathogenesis, diagnosis, treatment and preventative measures to address bacterial biofilm in mesh hernia surgery. Hernia surgeons should be familiar with these two new concepts which have the potential to cause major morbidity in hernia repair and know how to address them. METHODS: Ovid Medline and PubMed were searched for communications on "effective porosity" and "bacterial biofilm". RESULTS: There is a paucity of information in the literature of these conditions and their impact on outcomes following mesh hernia repair. CONCLUSIONS: We discuss the two concepts of effective porosity and biofilm and propose potential measures to reduce mesh-related complications. This includes choosing mesh with superior mesh construct and technical nuances in implanting mesh to improve effective porosity. Furthermore, measures to reduce bacterial biofilm and its consequences are suggested.

A prospective surveillance study of factor VIII inhibitor development in the Canadian haemophilia A population following the switch to a recombinant factor VIII product formulated with sucrose.

The introduction of new factor concentrates has, at times, resulted in an increase in inhibitor development; hence large systematic surveys of inhibitor development are necessary whenever new products are introduced. This study presents the results of a surveillance study conducted by the Inhibitor Subcommittee of the Association of Hemophilia Clinic Directors of Canada that evaluated inhibitor development in patients with haemophilia A following the switch to a second generation recombinant FVIII product (rFVIII-FS; Kogenate((R)) Bayer). Four hundred and sixty haemophilia A paediatric and adults patients from 17 Canadian Comprehensive Hemophilia Care Centers were enrolled in the study. Of these, 274 patients had evaluable data. Blood samples collected at baseline (prior to the switch to rFVIII-FS), and at 12 and 24 months following conversion were tested for inhibitors by the Nijmegen-modified Bethesda assay. Four subjects had positive inhibitor titres at baseline, with values ranging from 3.3 to 160 BU. Of the 274 patients who had baseline samples collected, 225 had postswitch samples collected at 12 months and 189 subjects had samples collected at 24 months. Only patients with positive baseline inhibitor titres (n = 4) had positive inhibitor titres at either the 12- or 24-month postswitch time points; therefore no de novo inhibitors developed over the 2-year evaluation period in this patient population. The results of this surveillance study suggest that the altered formulation of this recombinant FVIII concentrate was not associated with an increased incidence of inhibitor formation.

Laparoscopic live donor nephrectomy: the preliminary experience.

BACKGROUND: Recent improvements in video technology and surgical instrumentation have resulted in the application of minimally invasive techniques to many surgical procedures including splenectomy and adrenalectomy. Nephrectomy requires a long flank incision with division of abdominal musculature and possible subcostal nerve damage. Severe postoperative pain and a prolonged recuperative period may result, and the cosmetic outcome may not be satisfactory. A new surgical approach utilizing laparoscopic dissection and delivery of the kidney through a small incision was performed to circumvent these problems. The aim of this paper is to describe the technique of laparoscopic live donor nephrectomy (LLDN) and present the preliminary outcome. METHODS: Over the 12-month period between May 1997 and April 1998, 16 donors underwent donor nephrectomy by a laparoscopic approach. The procedure was assessed with regard to its safety, feasibility and advantages over the open method. RESULTS: All the nephrectomies were completed without conversion to an open procedure. The average postoperative pain score on a visual analogue scale of 1-10 was 2 in LLDN. The donors required 36 mg morphine on average over 36 h postoperatively. Postoperative stay averaged 3 days. One donor developed an infective complication along the wound drain tract which settled with adequate drainage and antibiotics. All the removed donor kidneys were transplanted with immediate good function. There were no surgical complications or graft losses. The recipients' serum creatinine was in the range of 96-181 mmol/L 3 months after transplantation. CONCLUSIONS: Significant potential advantages of LLDN include less postoperative pain, shorter hospitalization and decreased recuperative time. This preliminary experience indicates LLDN to be effective in terms of safety and feasibility.

Laparoscopic-assisted colonoscopic polypectomy: technique and preliminary experience.

BACKGROUND: The majority of colonic polyps found at endoscopy are suitable for diathermy snare excision via colonoscope. Due to location or size, some are deemed unsafe to treat in this manner and therefore require colectomy. This study describes the technique and early results of a laparoscopic-assisted colonoscopic polypectomy technique that can be used to manage such polyps and thereby avoid laparotomy and colectomy. METHODS: Colonoscopy with simultaneous laparoscopy was utilized to locate the site of the polyp. The colon was mobilized, if required, and the polyp resected by electrosurgical snare via the colonoscope while the serosal aspect of the colon was monitored laparoscopically. RESULTS: The technique has been tried successfully in six patients. Three polyps were in the cecum and three were within the left colon. The size of the polyps ranged from 3 to 7 cm. All polyps were benign on histological examination. The patients were discharged on the day following the procedure. There were no complications. CONCLUSIONS: The combination of laparoscopy with colonoscopic resection of a select group of large polyps represents a safe alternative to colonic resection.

Chemical composition of smoke produced by high-frequency electrosurgery in a closed gaseous environment. An in vitro study.

BACKGROUND: High-frequency (HF) electrocoagulation and cutting procedures produce smoke by high-temperature pyrolysis of tissues. As distinct from the experience of conventional surgery, electrosurgical smoke is produced in a closed gaseous environment during laparoscopic operations. As a result, toxic chemicals may be absorbed into the circulation. The effects of this absorption are not known. Furthermore, the chemical composition of electrosurgical smoke produced in an anoxic environment may be different from that produced in air. METHODS: Smoke was produced in vitro by HF electrocutting of fresh porcine liver in helium, CO2, and air-saturated closed environments. Smoke samples were collected and analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: The chemical constituents of electrosurgical smoke produced in air, CO2, and helium were similar. To date, 21 chemicals, some highly toxic, have been identified in the electrosurgical smoke produced in a closed environment. These consist of hydrocarbons, nitriles, fatty acids, and phenols. CONCLUSIONS: Electrosurgical smoke produced in a closed environment contains several toxic chemicals. The effects of these on cell viability, macrophage, and endothelial cell activation are not known but are being investigated. Meantime, measures to reduce smoke and evacuate it during endoscopic surgery are advisable.

Laparoscopic colectomy for cancer: a review.

BACKGROUND: The success of laparoscopic cholecystectomy in providing patient benefits in the immediate postoperative period has led to laparoscopic techniques being used for many other intra-abdominal procedures. Colorectal resection for malignancy is one of the more contentious applications of this new technology, because the postoperative benefits are more subtle and the long-term onco logical results are as yet unknown. METHODS: A review of the English-language literature was undertaken in order to collate and analyse all published series where 20 or more laparoscopic colectomies were performed. and where the indication for resection in the majority of cases was adenocarcinoma of the colon. RESULTS: Laparoscopic colectomy for cancer can be performed safely by experienced surgeons, although there is a considerable learning curve for the procedure. The expected benefits of minimal access surgery are provided by laparoscopic colectomy, although to a lesser extent than that seen with other procedures. The oncological safety of the procedure is as yet unproven. It is clear that an equivalent resection can be performed, but not whether this translates to an equivalent recurrence and survival rate. Reports of isolated port site recurrences are of concern. CONCLUSIONS: Early results of laparoscopic colectomy for cancer are encouraging, although the fate of this procedure rests with the analysis of the large multicentre prospective randomized trials currently under way, particularly with regard to the long-term recurrence and survival rates.

Cytotoxicity of electro-surgical smoke produced in an anoxic environment.

BACKGROUND: The effect on cell viability of smoke produced during high-frequency electro-surgery has not been previously reported. The aim of this study was to produce smoke in vitro, in a closed environment similar to that encountered in minimal access surgery, and to test its cytotoxic effects on cultured cells. METHODS: Pig liver was cut repeatedly with an electro-surgical hook knife, and the smoke generated was collected and equilibrated with cell culture medium. MCF-7 human breast carcinoma cells were exposed briefly to various dilutions of this medium and tested for clonogenicity. RESULTS: Electro-surgical smoke produced in a helium environment reduced the clonogenicity of the MCF-7 human breast carcinoma cells in a dose-dependent manner, falling to 30% when the cells were exposed to undiluted medium for 15 minutes. CONCLUSIONS: We conclude that electro-surgical smoke is cytotoxic. The sublethal effects at lower dilutions are currently being investigated.

Total radiated power, infrared output, and heat generation by cold light sources at the distal end of endoscopes and fiber optic bundle of light cables.

BACKGROUND: Skin burns and ignition of drapes have been reported with the use of cold light sources. The aim of the study was to document the temperature generated by cold light sources and to correlate this with the total radiated power and infrared output. METHODS: The temperature, total radiated power, and infrared output were measured as a function of time at the end of the endoscope (which is inserted into the operative field) and the end of the fiber optic bundle of the light cable (which connects the cable to the light port of the endoscope) using halogen and xenon light sources. RESULTS: The highest temperature recorded at the end of the endoscope was 95 degrees C. The temperature measured at the optical fiber location of the endoscope was higher than at its lens surface (p < 0.0001). At the end of the fiber optic bundle of light cables, the temperature reached 225 degrees C within 15 s. The temperature recorded at the optical fiber location of all endoscopes and light cables studied rose significantly over a period of 10 min to reach its maximum (p <0.0001) and then leveled off for the duration of the study (30 min). The infrared output accounted only for 10% of the total radiated power. CONCLUSIONS: High temperatures are reached by 10 min at the end of fiber optic bundle of light cables and endoscopes with both halogen and xenon light sources. This heat generation is largely due to the radiated power in the visible light spectrum.

Transcystic biliary decompression after direct laparoscopic exploration of the common bile duct.

BACKGROUND: A purpose-designed transcystic common bile duct (CBD) decompression cannula is described for use as an alternative to T-tube insertion following laparoscopic direct CBD exploration. This permits safe primary closure of the choledochotomy. METHODS: Following direct supraduodenal laparoscopic clearance of large common bile duct stones, the biliary decompression cannula is inserted percutaneously inside its peel-away sheet over a guide-wire into the CBD via the cystic duct. When in place, the cannula is secured to the cystic duct by two catgut extracorporeal Roeder knots and the choledochotomy is then closed. The terminal multiperforated S-shaped segment of the Cuschieri biliary decompression cannula prevents postoperative dislodgement. RESULTS: Transcystic decompression of the extrahepatic biliary tract using the Cuschieri cannula has been used in 12 patients who underwent laparoscopic supraduodenal CBD exploration for large or occluding stones. There was no instance of postoperative dislodgement of the cannula and all patients had effective drainage of the common bile duct (average 300 ml bile per 24 h). The procedure was uncomplicated in all but one patient who developed self-limiting leakage from the CBD suture line in the early postoperative period. The median hospital stay after surgery was 4 days, with a range of 3 to 10 days. The cystic duct decompression cannula was capped and sealed under an occlusive dressing at the time of discharge. Removal of the cannula was carried out without any complications as a day case 11-16 days after surgery. CONCLUSIONS: Transcystic biliary decompression is safe and effective. The experience with is use indicates that compared to T-tube drainage, transcystic decompression may accelerate recovery and reduce the hospital stay in patients following laparoscopic direct exploration of the CBD. Its insertion is less technically demanding than placing a T-tube through the choledochotomy. Transcystic decompression with complete primary closure of the CBD realizes the full benefits of the single-stage management of common bile duct calculi and permits confirmation of complete stone clearance after surgery.

HPLC determination of biologically active thiols using pre-column derivatisation with 5,5'-dithio-(bis-2-nitrobenzoic acid).

5,5'-Dithio-(bis-2-nitrobenzoic acid), Ellmans reagent (ESSE), is used as a pre-column derivatisation reagent for the determination of biologically active thiols by HPLC. D-penicillamine, N-acetyl-d-penicillamine, N-acetylcysteine, cysteine, captopril and thiomalic acid all give well resolved derivatives. The calibration graph and reproducibility (%R.S.D. +/- 1.3%) for the analysis of glutathione indicates that the method could be used for quantitative analysis. ESSE is widely used as a reagent in thiol determinations by electronic spectroscopy via the detection of the Ellmans anion (ES-) generated without any prior separation procedures. However, there are considerable reservations over its use for the spectrophotometric determination of thiols because of the possibility of side reactions which generate another Ellmans based species (ESO2-). The assay described determines the thiol as a derivatised mixed disulphide (ESSR) and since speciation between the anion ES- and the oxidation product ESO2- occurs it enables the process of oxidation to be monitored simultaneously.

Alcoholism: a controlled trial of "treatment" and "advice".

Two groups of alcoholics received either one counseling session or several months of in- and outpatient treatment. One year later there were no significant differences in outcome between the two groups.

The cohesiveness of alcoholism-complicated marriages and its influence on treatment outcome.

One-hundred husbands, diagnosed as suffering from alcoholism, and their wives, were followed up twelve months after initial consultation and assessment. Follow-up information was complete in 89 cases. On the basis of both husband and wife accounts of the husband's drinking behaviour during the follow-up period, and their assessment of the drinking problem at twelve-months follow-up, 28 were classified as having a 'good' outcome and 29 as having a 'bad' outcome. In the remaining 32 cases outcome was considered 'equivocal'. A composite measure of marital cohesion was predictive of twelve-month outcome classification, cohesive marriages being significantly more likely to have a good outcome. The measure of marital cohesion was based upon husband and wife reports of mutual affection and of husband involvement in family tasks, favourable spouse perceptions and meta-perceptions, and optimism about the future of the marriage. Composite measures of dominance balance within the marriage were not predictive of outcome. Husband's job status, husband's self-esteem, and wife's reported hardship were not independent of marital cohesion, and were themseleves predictive of twelve-months outcome. When these variables were partially controlled it was found that marital cohesion remained predictive for husbands with relatively low status jobs and husbands with relatively low levels of self-esteem. It is an over-simplification to state that either the marriage, the spouse, or the severity of the patient's condition is alone the cause of variation in outcome. It is possible to integrate these findings with those of other studies on the influence of family variables on the outcom of conditions other than alcoholism. Together these studies suggest a general hypothesis linking a breakdown in the cohesiveness, or mutual rewardingness, of family relationships and unfavourable outcomes following treatment or consultation for psychological disorder.

Self-reported coping behavior of wives of alcoholics and its association with drinking outcome.

The frequency of the use of coping behavior by wives of alcoholics was found to be related to their husband's drinking outcome. In general, a high frequency of coping behavior was associated with a poor outcome, but some components of coping behavior were more likely than others to be linked with a poor prognosis.