Prevalence of bacterial burden on macroscopic contaminants of orthopaedic surgical instruments following sterilization.

BACKGROUND: Macroscopic contamination of orthopaedic instruments with particulates, including cortical bone and polymethyl methacrylate (PMMA) bone cement, that have previously undergone pre-operative sterilization is frequently encountered peri- or intraoperatively, calling into question the sterility of such instruments. AIM: To determine if macroscopic contaminants of orthopaedic surgical instrumentation maintain a bacterial burden following sterile processing, and to determine the most commonly contaminated instruments and the most common contaminants. METHODS: Macroscopic contaminants in orthopaedic instrument trays were collected prospectively at a single tertiary referral centre over a 6-month period from August 2021 to May 2022. When identified, these specimens were swabbed and plated on sheep blood agar. All specimens were incubated at 37 °C for 14 days, and inspected visually for colony formation. When bacterial colony formation was identified, samples were sent for species identification. RESULTS: In total, 33 contaminants were tested, and only one contaminant was found to be growing bacterial colonies (Corynebacterium sp.). The items most commonly found to have macroscopic contamination were surgical trays (N=9) and cannulated drills (N=7). The identifiable contaminants were bone (N=10), PMMA bone cement (N=4) and hair (N=4). Eleven macroscopic contaminants were not identifiable. CONCLUSION: This study found that 97% of macroscopic orthopaedic surgical instrument contaminants that underwent sterile processing did not possess a bacterial burden. Contaminants discovered during a procedure are likely to be sterile, and do not pose a substantially increased risk of infection to a patient.

Hinged surgical instruments: efficacy of double manual cleaning versus automated cleaning on biofilm removal.

The efficacy of double manual cleaning (DMC) with enzymatic detergent followed by alkaline detergent on biofilm removal on hinged surgical instruments was compared to automated cleaning. Biofilm-covered haemostatic forceps were divided into four groups: positive control (soaked in sterile water); DMC; DMC plus extra brushing of the inner hinge; and automated cleaning. All DMC, DMC plus brushing the hinge, and automated cleaning significantly (P < 0.001) reduced 94.8%, 99.8%, and 100% viable bacteria and 82.3%, 93.8%, and 95.1% residual protein, respectively, compared to positive control. DMC instruments had significantly more viable bacteria (P < 0.05) and residual protein (P < 0.01) than those in instruments subjected to DMC with hinge brushing and automated cleaning. However, there was no significant difference in residual protein between DMC with hinge brushing and automated cleaning. In sterilizing service units with no access to automated cleaning equipment, it is important to brush the inner hinge during manual cleaning, and DMC plus brushing the inner hinge could be considered a viable alternative for cleaning hinged surgical instruments.

Bacteriological and mechanical impact of the Sterrad sterilization method on personalized 3D printed guides for mandibular reconstruction.

Surgical cutting guides are increasingly used for maxillofacial reconstruction. They are usually provided by laboratories. In recent years, surgical teams have published studies on the possibility of manufacturing their own cutting guides thanks to 3D printers. The object of this study is to analyze the impact of the sterilization on the surface of those personalized models and to assess the effectiveness of sterilization. Using the data from high-resolution CT scan of patient, 3D models were generated through computerized assisted design and fabricated with a 3D printer using Acrylonitrile Butadiene Styrene (ABS). For the sterilization, a Sterrad method was used. In order to evaluate the effectiveness of sterilization, 3D models were artificially contaminated with several bacterial reference strains, sterilized and finally cultured. The surfaces and mechanical modifications were analyzed before and after sterilization with infrared spectrometry, surface contact angle, extensometer, scanning electron microscopy and atomic force microscopy. Ten models of different shapes and 24 samples were fabricated, sterilized and analyzed. The 3D models were designed in 48 h, printed in an average of 122 min and underwent a 47 min cycle of sterilization. All experimentally contaminated 3D models were negative in culture, with at least, a six log reduction of the initial inoculum. The hydrophobicity and roughness of the surface suffered few changes. The reproducibility of this procedure was proved by identical results in the three sterilization rounds. Using Sterrad process for the sterilization of ABS printed material doesn't represent a bacterial risk for the patient. It is a feasible and safe innovative reconstructive method that can save time particularly for oncological cases.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND: Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination. METHODS: The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes. RESULTS: 17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections. CONCLUSION: The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.

How clean is clean enough? An observational pilot study to assess central sterilization processing efficacy with adenosine triphosphate levels.

BACKGROUND: There is strong evidence showing the need for quantitative assessment of the efficacy of cleaning medical devices. Studies comparing visual and microscopic analysis have demonstrated that visual inspection alone is insufficient to determine cleanliness. OUR OBJECTIVE WAS TO: collect baseline adenosine triphosphate testing data for surgical instruments to inform future quality improvement programs, and to develop a process to comply with standards recommended by the Association for the Advancement of Medical Instrumentation. METHODS: The central sterilization processing department (CSPD) identified difficult to clean tools in hip, spinal fusion, and colon procedures. Instruments used during the procedures were swabbed at arrival to the CSPD, after manual washing, and after a standard 24-minute machine wash cycle. Each instrument was swabbed in a uniform manner on surface areas including hinged joints and teeth, consistent with manufacturer recommendations. Instruments were tagged to ensure accuracy of tracking. RESULTS: The mean relative light unit (RLU) readout of all instruments on entry to the CSPD, postmanual wash, and postmachine wash was 240,416, 3,352, and 47, respectively. A total of 97.7% of all instruments had a passable final RLU readout. One Rongeur had a failed final RLU readout of 171. CONCLUSIONS: This study suggests that the current cleaning process is adequate for the instruments tested. Ongoing quality assessment would be beneficial to validate other instruments.

Incidence of Propionibacterium acnes in arthroscopic rotator cuff repair.

BACKGROUND: Recently, Propionibacterium acnes was reported to be involved in postsurgical outcomes. We investigated the detection rate of P. acnes and clinical features of P. acnes infection following arthroscopic rotator cuff repair. METHODS: Samples were collected from skin swabs before preparation, swabs of the synovium, sutures, and swabs from the arthroscope tip. We evaluated age, sex, presence of diabetes mellitus, preoperative contracture, operation time, blood test, Japanese Orthopaedic Association (JOA) scores, cuff integrity, deep infection, and positive inoculation rate. RESULTS: We studied 90 patients (59 men and 31 women). Mean age was 60.6 years. Cultures of P. acnes showed a 65.5% positive superficial colonization rate (78.0%, male; 41.9%, female). Among the synovium swabs, P. acnes was detected in 13.6% and 0% of patients positive and negative for skin colonization with P. acnes, respectively. Positive culture was not correlated with age, sex, presence of diabetes mellitus, preoperative contracture, blood test, JOA score, cuff integrity, deep infection, operation time, and blood test date. CONCLUSIONS: P. acnes was detected at a higher rate in the skin of male patients. Patients with P. acnes detected on the skin showed higher rates of detection in the synovium. These findings suggest that the route of infection is via contamination. LEVEL OF EVIDENCE: Diagnostic level III; Case-control study.

Effectiveness of manual versus automated cleaning on Staphylococcus epidermidis biofilm removal from the surface of surgical instruments.

BACKGROUND: Biofilm removal is a challenge during surgical instrument processing. We analyzed the time required for Staphylococcus epidermidis to form biofilms on surgical instruments, and how cleaning methods removed them. METHODS: Different areas (ratchet, shank, and jaw) of straight crile forceps were contaminated by soaking in Tryptic Soy Broth containing 106 colony forming units (CFU)/mL of S epidermidis for 1, 2, 4, 6, 8, and 12 hours. S epidermidis adhesion and removal, after manual or automated ultrasonic cleaning, was evaluated by microbiological culture and scanning electron microscopy. RESULTS: Microbial load increased with time (101-102 CFU/cm2 after 1 hour; 104 CFU/cm2 after 12 hours). Exopolysaccharide was detected after 2 hours and gradually increased thereafter. Bacterial load was reduced by 1-2 log10 after manual cleaning and 1-3 log10 after automated cleaning, but biofilms were not completely eliminated. In general, bacterial load was lower in shank fragments. This difference was significant at 6 hours. CONCLUSIONS: Rapid adhesion of S epidermidis and exopolysaccharide formation was observed on surgical instruments. Automated cleaning was more effective than manual cleaning, but neither method removed biofilms completely. The precleaning conditions and the forceps design are critical factors in processing quality.

Detection of Cutibacterium acnes in arthroscopic rotator cuff and bankart repair.

BACKGROUND: We evaluated the detection rate for Cutibacterium acnes (C. acnes) in patients who underwent arthroscopic cuff repair and Bankart repair. METHODS: Arthroscopic cuff repair was performed in 105 patients (R group) and arthroscopic Bankart repair was performed in 29 patients (B group). Skin swabs prior to antisepsis, intraoperative synovial swabs of the glenohumeral joint (immediately after incision and prior to wound closure), suture of suture anchor, and postoperative swabs from the tip of arthroscope were cultured. Evaluation criteria were compared between groups and included the presence or absence of diabetes mellitus, operation time, frequency of preoperative injections, deep infections, and detection rate of C. acnes in multiple regions of the body. RESULTS: There were 14 patients (12.2%) in the R group and one patient in the B group (3.6%) with diabetes mellitus, and no significant difference was found between the two groups. The frequency of injections to the shoulder was significantly greater in the R group at 3.6 ± 4.2 times compared to the B group at 1.6 ± 2.0 times. There were no deep infections in either groups. The detection rate for C. acnes was significantly greater in the synovial swabs alone (skin swabs for R and B groups, 42.3% and 47.6%, respectively; synovial swabs, 10.4% and 1.8%; suture, 8.7% and 0%; tip of arthroscope, 4.3% and 0%). CONCLUSIONS: A significantly greater number of C. acnes samples were detected from synovial swabs of cuff tears, suggesting that its presence may be due to preoperative injections to the shoulder.

Adenosine Triphosphate-Bioluminescence Technology as an Adjunct Tool to Validate Cleanliness of Surgical Instruments.

Perioperative and sterile processing department personnel commonly use visual inspection to validate surgical instrument cleanliness. This validation process does not detect microbes (eg, bacteria, viruses) and the resultant inadequately decontaminated instruments can put patients at risk for developing surgical site infections. Sterile processing department personnel should use a rapid, straightforward method to validate surgical instrument cleanliness objectively. During a quality improvement project at a military treatment facility, staff members found that adenosine triphosphate (ATP)-based technology was a viable and affordable solution for detecting bioburden and validating cleaning practices. The project design compared manually and mechanically cleaned cannulated instruments (59 of each) and identified 16 contaminated instruments, 14 of which had been manually cleaned. The contamination rate after mechanical cleaning was significantly lower (P = .0022) compared with manual cleaning. As a result of this quality improvement project, this facility fully implemented the technology to validate instrument cleaning.

Fulminant scleral abscess secondary to infected scleral buckle with Moraxella species.

We here report a case of scleral buckle infection with fulminant scleral abscess secondary to Moraxella species. A 54-year-old chronic alcoholic male with a history of retinal detachment repair, with scleral buckle 8 years prior, presented with complaints of severe pain, redness, and swelling in the right eye since 2 weeks. The patient was diagnosed with scleral buckle infection, the buckle was removed, and cultures revealed Moraxella species. The postoperative course included fulminant scleral abscess treated with dual antibiotic therapy that included ceftriaxone and moxifloxacin. All systemic antibiotics were discontinued after 3 weeks, retina remained attached, and no recurrence occurred over a 1-year follow-up. Moraxella, though commonly associated with bacterial keratitis, can also lead to buckle infection, especially in chronic alcoholic and immunocompromised patients. In buckle infection, infected buckle along with sutures should be immediately removed without damaging underlying compromised sclera. Lastly, culture and drug sensitivity play a very important role in buckle infections.

Performance and microbiological safety testing after multiple use cycles and hydrogen peroxide sterilization of a 5-mm vessel-sealing device.

OBJECTIVE: To evaluate the functional and microbiological safety of a single-use laparoscopic vessel-sealing device in a multiuse setting. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Twelve 5-mm LigaSure Maryland jaw devices. METHODS: Handsets underwent repeated test cycles until failure. The handset packaging was opened, and handsets were agitated in phosphate-buffered saline (PBS). The PBS was removed, centrifuged, and submitted for culture. Canine ovariectomy was simulated on cadaveric tissue, after which vascular seal quality was evaluated by pressure testing of sealed porcine carotid arteries. The handsets were cleaned and sterilized with hydrogen peroxide gas and repackaged. RESULTS: Mean ± SD cycles to failure was 7.7 ± 2.8, with a minimum of 4 and a maximum of 12 use cycles achieved. Eleven of the 12 handsets failed by failure of handset activation after depression of the activation trigger. Only 1 handset failed to hold an adequate vascular seal under 300 mm Hg of pressure. No handset exhibited positive bacterial culture at any cycle. CONCLUSION: The sterilization method used in this study resulted in an excellent microbiological safety profile. Most of the handsets failed by activation button failure. CLINICAL SIGNIFICANCE: Under the conditions of this study, hydrogen peroxide sterilization achieved microbiological safety. Handsets can successfully be reused until activation button failure without negative effects on the vascular seal or increased risk of infection to the patient.

Ultrasound-triggered antibiotic release from PEEK clips to prevent spinal fusion infection: Initial evaluations.

Despite aggressive peri-operative antibiotic treatments, up to 10% of patients undergoing instrumented spinal surgery develop an infection. Like most implant-associated infections, spinal infections persist through colonization and biofilm formation on spinal instrumentation, which can include metal screws and rods for fixation and an intervertebral cage commonly comprised of polyether ether ketone (PEEK). We have designed a PEEK antibiotic reservoir that would clip to the metal fixation rod and that would achieve slow antibiotic release over several days, followed by a bolus release of antibiotics triggered by ultrasound (US) rupture of a reservoir membrane. We have found using human physiological fluid (synovial fluid), that higher levels (100-500 µg) of vancomycin are required to achieve a marked reduction in adherent bacteria vs. that seen in the common bacterial medium, trypticase soy broth. To achieve these levels of release, we applied a polylactic acid coating to a porous PEEK puck, which exhibited both slow and US-triggered release. This design was further refined to a one-hole or two-hole cylindrical PEEK reservoir that can clip onto a spinal rod for clinical use. Short-term release of high levels of antibiotic (340 ±â€¯168 µg), followed by US-triggered release was measured (7420 ±â€¯2992 µg at 48 h). These levels are sufficient to prevent adhesion of Staphylococcus aureus to implant materials. This study demonstrates the feasibility of an US-mediated antibiotic delivery device, which could be a potent weapon against spinal surgical site infection. STATEMENT OF SIGNIFICANCE: Spinal surgical sites are prone to bacterial colonization, due to presence of instrumentation, long surgical times, and the surgical creation of a dead space (≥5 cm3) that is filled with wound exudate. Accordingly, it is critical that new approaches are developed to prevent bacterial colonization of spinal implants, especially as neither bulk release systems nor controlled release systems are available for the spine. This new device uses non-invasive ultrasound (US) to trigger bulk release of supra-therapeutic doses of antibiotics from materials commonly used in existing surgical implants. Thus, our new delivery system satisfies this critical need to eradicate surviving bacteria, prevent resistance, and markedly lower spinal infection rates.

Complex design of surgical instruments as barrier for cleaning effectiveness, favouring biofilm formation.

BACKGROUND: Inadequately reprocessed reusable surgical instruments (RSIs) may harbour infectious agents which may then be transferred to a suitable site for replication. AIM: To determine the cumulative effect of 20 cycles of contamination, cleaning (manual or manual followed by automated) and steam sterilization on high-complex-design RSIs used for orthopaedic surgery. METHODS: New flexible medullary reamers and depth gauges were contaminated by soaking in tryptone soya broth, containing 5% sheep blood and 109 cfu/mL of Staphylococcus aureus (ATCC 25923), for 5 min. To mimic a worse-case scenario, RSIs were dried 7 h and subjected to either (a) rinsing in distilled water, (b) manual cleaning or (c) manual plus automated cleaning (reference standard), and steam sterilization. The contamination, cleaning, and sterilization cycle was repeated 20 times. Adenosine triphosphate (ATP) was measured after cleaning procedures; microbial load and residual protein were measured following the 10th and 20th reprocessing, in triplicate. Scanning electron microscopy (SEM) was used to confirm soil and biofilm presence on the RSIs after the 20th reprocessing. FINDINGS: Manual and manual plus automated cleaning significantly reduced the amount of ATP and protein residues for all RSIs. Viable bacteria were not detected following sterilization. However, SEM detected soil after automated cleaning, and soil, including biofilms, after manual cleaning. CONCLUSION: Soil and/or biofilms were evident on complex-design RSIs following 20 cycles of contamination and reprocessing, even using the reference standard method of cleaning. Although the depth gauges could be disassembled, biological residues and biofilm accumulated in its lumen. The current design of these RSIs prevents removal of all biological soil and this may have an adverse effect on patient outcome.

Estudio comparativo del indicador biológico Velocity con el Cyclesure 24 / No disponible

Debido a que los hospitales tienen una cantidad de material quirúrgico muy ajustada, y a la cantidad de intervenciones, especialmente por la mañana, los tiempos de limpieza y esterilización tienen que reducirse al mínimo posible. La esterilización a baja temperatura requiere control biológico en todos los ciclos (sea cual sea método usado) y en peróxido de hidrógeno se ve-nía utilizando indicadores biológicos (IB) que requerían 24 horas de incubación. La aparición del nuevo IB Velocity que necesita 30 minutos, reduce este tiempo de modo drástico. Hemos realizado un estudio comparando los resultados obtenidos en diferentes ciclos con ambos IB, encontrando una correlación completa

Since hospitals have constrained availability of surgical material and the schedule of interventions is more common in the morning, the time needed for cleaning and sterilization should be reduced to the minimum. Low temperature sterilization requires biological control in all cycles (whatever method is used) and hydrogen peroxide has been using biological indicators (IB) that required 24 hours of incubation. The appearance of the new IB Velocity that needs 30 minutes, reduces this time drastically. We have carried out a study comparing the results obtained in different cycles with both IBs, finding a complete correlation

Evaluation of stainless steel surgical instruments subjected to multiple use/processing.

BACKGROUND: To determine the effect of multiple use and processing cycles on instrument quality over the life of stainless steel, complex designed clinical surgical instruments. METHODS: Steam sterilised surgical instruments due to be discarded from Australian hospitals, because of loss of functionality, were assessed for contaminating protein and bacteria using the bicinchoninic acid protein assay and microbial culture, respectively. Biofilm presence and instrument damage were visually confirmed by scanning electron microscopy (SEM). Instruments were categorised into hinged/serrated, screw, cannulated, flexible, and irregular surfaced (but not hinged) according to their design. RESULTS: Protein contamination ranged from 24 µg on the new screw to 3,756,046 µg contaminating a discarded forceps. The more complex the instrument design the higher the protein contamination. All samples were culture negative, however, biofilm was visually confirmed on 4/8 instruments tested using SEM. SEM also detected soil, holes or black stains on all the instruments. CONCLUSION: "Ready to use" surgical instruments that underwent multiple uses and processing cycles were contaminated with high amounts of protein, and microscopy revealed the presence of soil, structural damage, black stains and biofilm. While less affected new but multiply processed screws also showed soil and biofilm contamination. These findings highlight the need for further research into determining what is the "life" of stainless steel instruments and development of standard criteria for evaluating when to "retire" an instrument.

Reprocessing safety issues associated with complex-design orthopaedic loaned surgical instruments and implants.

BACKGROUND: The acquisition of reusable surgical instruments (RSIs) through loaner system is a worldwide phenomenon, particularly in orthopaedic surgeries. Loaner sets contain high-complex design RSIs, which are very difficult to clean, and also include single use implants, such as screws, that remain in the surgical tray and are subjected to multiple reprocessing until they are implanted. Inadequate cleaning of SI and various exposures of single-use implants to physical, chemical and biological agents can compromise their quality/safety and promote biofilm formation. The difficulty in cleaning is compounded in middle and low-income countries where automated cleaning infrastructure at sterilizing service units is often unavailable, and thus manual cleaning only is performed. Thus, we aimed to determine the condition of orthopaedic loaned sets when delivered to the hospital, assess the quality of complex-design RSIs reprocessed by manual cleaning, and evaluate the effect of multiple reprocessing on single-use implant (screw). METHODS: Flexible medullary reamers (FMRs), depth gauges and screws used for femur intramedullary nailing, in clinical use for >1 year, were obtained from three Brazilian loaner companies and assessed for residual ATP, protein, bacterial contamination, endotoxin and/or biofilm at delivery at the hospital, following cleaning and steam sterilisation. RESULTS: Before cleaning, blood was visible on a RSIs tray, and RSIs/screws were contaminated with high amounts of ATP, protein and bacteria. Visible soil was released during brushing of a FMR lumen and, following cleaning, the inner layer of 34/40 were visible soiled, and over 5/8 were protein test positive. Following sterilisation, biofilm and soil, including fragments appearing to be bone, were detected by scanning electron microscopy on RSIs/screws. A sterilised FMR revealed visible soil on the inner layer. Endotoxin tests were negative. CONCLUSION: The contaminated condition of loaned-complex-designed RSIs/screws upon arrival at the hospital and after reprocessing points to the insufficiency of manual reprocessing and management practices related to this instruments/implants. A multidisciplinary approach involving expert in design/manufacture, regulating, managing, reprocessing and surgeons is suggested to improve RSIs manufacture that enables complete decontamination and maintain the surgical patient safety.

Dual Ring Wound Protector Reduces Circular Stapler Related Surgical Site Infections in Patients Undergoing Laparoscopic Roux-En-Y Gastric Bypass.

BACKGROUND: While there are various techniques to create the gastrojejunostomy during a laparoscopic Roux-en-Y gastric bypass (LRYGB), many surgeons prefer using a circular stapler. One drawback of this method, however, is the higher incidence of surgical site infections (SSIs). To investigate the effect of a dual ring wound protector on SSIs during LRYGB. METHODS: In April 2016, our bariatric surgical group implemented an intervention whereby a dual ring wound protector in conjunction with a conical EEA stapler introducer was used when creating the gastrojejunostomy. SSIs from pre- and post-intervention were compared using Fisher's exact test. Only LRYGBs performed with a circular stapler were included in our analysis. Student's t test and χ2 were used to compare pre- and post-intervention groups with respect to demographics and co-morbidities. RESULTS: Between April 2015 and January 31st, 2017, our surgeons performed 158 LRYGBs using a circular stapler for the gastrojejunostomy. There were 84 patients (53%) in the pre-intervention group and 74 (47%) in the post-intervention group. The pre- and post-intervention groups were not statistically different. The SSI rate for the pre-intervention group was 9.5% while the SSI rate was 1.35% in the post-intervention group (p = 0.0371). The use of a dual ring wound protector for LRYGBs with circular stapled gastrojejunostomy was associated with an 86% relative risk reduction in SSIs. CONCLUSION: Using a dual ring wound protector in conjunction with a conical EEA introducer for LRYGBs with circular stapled gastrojejunostomy significantly decreased SSIs.

Microbial Load of Trocars: Potential Source of Contamination and Surgical Site Infection.

Surgical site infection (SSI) is a common complication that is associated with delayed recovery, prolonged length of hospital stay, exorbitant cost, and mortality. The present prospective longitudinal study aimed to evaluate the relationships between the microbial load of trocars used in laparoscopic gynecological surgery, microbiota in surgical sites, and SSI. The final sample consisted of 24 patients, including 68 swab samples and 48 trocars. Microorganisms were recovered in 100.0% of the swabs collected from the umbilicus and vaginal fornix and in 58.3% (14/24) of the swabs collected from skin at the left McBurney's point. Most of the samples collected from trocars (87.5%) did not exhibit bacterial growth, suggesting proper disinfection. In addition, antisepsis was effective for decolonization of the skin to create an aseptic surgical field.

Is retained bone debris in cannulated orthopedic instruments sterile after autoclaving?

AIMS: Cannulated surgical instruments may retain biologic debris after routine cleaning and sterilization. Residual debris after cleaning is assumed to be sterile; however, there is no experimental basis for this assumption. The purpose of this study was to determine the sterility of retained biodebris found within cannulated surgical instruments after autoclave sterilization. MATERIALS AND METHODS: Fifteen cannulated drill bits were used to drill pig scapulae to create a plug of bone that was exposed to a mixture of Bacillus cereus, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus for 60, 120, or 180 minutes prior to sterilization. The drill bits were autoclave sterilized using standard settings. The "sterilized" bone cores were then incubated in solution and streak-plated on blood agar. RESULTS: All 3 positive controls were positive for the experimental bacteria. Two negative controls were positive for contaminant bacteria. A B. cereus strain was recovered from 1 of the experimental group drill bits in the 180-minute group. Pulsed-field gel electrophoresis confirmed that the recovered B. cereus strain was identical to the experimental inoculate. CONCLUSION: Retained biodebris in cannulated drills may not be sterile after standard autoclave sterilization. In addition, delay of surgical instrument reprocessing may increase the risk of resistant contamination.