Investigation of Antibiotic Release from Bone Allograft in an Experiment on Rabbits

BACKGROUND: The treatment of chronic osteomyelitis, despite the use of new methods, is still an urgent problem. Local use of antibacterial drugs in combination with systemic antibiotic therapy has become popular in recent decades. Autologous bone grafts are considered ideal for bone defects filling. Different methods of allograft preparation may have differences in the rate and duration of antibiotic release. Moreover, it can affect the effectiveness of microbial agent eradication. The study analyzed the differences in the release of gentamicin from different types of allografts in dynamics and methods of preparation: «PerOssal» medium, whole bone allograft soaked in antibiotic, whole bone allograft, welded with an antibiotic, and perforated bone allograft soaked in an antibiotic solution. AIM: The objective of the study was to study the stability of antibiotic release and to determine the effectiveness of local transport systems. Evaluation of the difference in gentamicin release from different types of allografts in dynamics and methods of preparation had been realized: “PerOssal” medium, whole bone allograft soaked in antibiotic, whole bone allograft welded with an antibiotic, and perforated bone allograft, soaked in antibiotic solution. MATERIALS AND METHODS: The research was conducted between September 2020 and March 2021. The experiments were performed on 120 laboratory rabbits (weight – 3000–3500 g, age – 6–8 months), which were divided into four groups (30 animals in each group). Group 1 consisted of animals treated with “PerOssal.” The whole bone allograft soaked in an antibiotic was used in the treatment of animals of Group 2. The whole bone allograft, welded with an antibiotic, was used in the treatment of animals of Group 3. Perforated bone allograft soaked in an antibiotic was used in Group 4. Osteomyelitis of the proximal femur was formed in experimental animals. RESULTS AND DISCUSSION: Statistically insignificant decrease in the concentration of gentamicin was observed by the 7th day in all experimental groups. In rabbits whose bone defect was filled with a whole bone allograft welded with antibiotic and perforated bone allograft impregnated with an antibiotic (Groups 3 and 4), the most stable concentration of gentamicin was noted throughout the study period. Statistically significant differences were revealed between the experimental groups in relation to the dynamics of changes in the concentration of gentamicin in blood plasma. It was found that the group using the biodegradable material “PerOssal” on the 1st day showed a high concentration of the antibiotic in the blood plasma. However, by the 2nd day, a lower concentration of the antibiotic was recorded compared to all comparison groups of the bone allograft. CONCLUSIONS: The results of the analysis of the dynamics of gentamicin concentration may indicate significant differences between the methods of graft preparation, especially in the relationship with antibiotic release into the blood plasma. The most stable antibiotic concentration was registered in the groups of animals that underwent the filling of bone defect using a whole bone allograft welded with an antibiotic and a perforated bone allograft impregnated with antibiotic. A significant decrease of gentamicin concentration in the femur homogenate by the 7th day after transplantation was observed when using a whole bone allograft impregnated with an antibiotic. At the same time, a stable concentration of the antibiotic in the blood plasma was registered. The highest initial antibiotic concentration in the homogenate with a gradual decrease over 7 days was observed when using the antibiotic-impregnated biodegradable material “PerOssal.”

Post-Mastectomy Surgical Pocket Irrigation With Triple Antibiotic Solution vs Chlorhexidine Gluconate: A Randomized Controlled Trial Assessing Surgical Site Infections in Immediate Tissue Expander Breast Reconstruction

Background Post-mastectomy pocket irrigation solution choice is debated and primarily surgeon dependent. We compare triple antibiotic solution (TAS) to 0.05% chlorhexidine gluconate (CHG). Objectives The purpose of this study was to determine surgical site infection (SSI) rates after using TAS vs CHG for breast pocket irrigation in immediate tissue expander breast reconstruction. Methods A prospective, blinded, randomized controlled trial was performed in patients (18-81 years old) undergoing bilateral mastectomy with tissue expander (TE) reconstruction. In each patient, one mastectomy pocket was randomized to TAS and the other to CHG. Both the TE and the pocket were irrigated in the respective solution. The primary outcome was the incidence of surgical site infections (SSI). Secondary outcomes were rates of mastectomy flap necrosis, hematoma, and seroma. Results Eighty-eight patients undergoing bilateral immediate breast reconstruction were enrolled. Demographic and operative characteristics were equivalent as each patient served as their own control. Between the TAS and CHG groups, there was no difference in the incidence of SSI (5 [4.5%] vs 7 [8.0%], p = 0.35), including minor infections (2 [2.3%] vs 1 [1.1%], p = 0.56), major infections (2 [2.3%] vs 6 [6.8%], p = 0.15), and those resulting in explantation (2 [2.3%] vs 5 [4.5%], p = 0.25). There was also no difference in necrosis, hematoma, or seroma formation. No patients who developed SSI had radiation. Conclusions This study does not demonstrate a statistically significant difference in SSI between TAS and CHG irrigation, though TAS approached statistical significance for lower rates of infectious complications.

Pharmacokinetics of Vancomycin Installation in Pleural Cavity—A Clinical Case with Animal Experiments

(1) background: Postpneumonectomy empyema is often observed in patients after a complete pneumonectomy. The management of these cases can be challenging when the condition of patients is complicated by a bronchopleural fistula. A multidisciplinary approach is required to manage these critically ill patients, especially when they are not suitable candidates for surgery; (2–3) Methods & Results: we report a case of successfully treated postpneumonectomy empyema caused by a bronchopleural fistula and pharmacokinetics of vancomycin installation in pleural cavity using rat experiments; (4) Conclusions The experiments provide evidence that irrigation of the pleural cavity with an antibiotic solution containing vancomycin may be an efficient treatment strategy, especially in the case of an MRSA infection in the thickened pleura.

Aspecte morfopatologice si strategii de preventie a contracturii capsulare după augmentarea mamara cu implante

Breast augmentation with silicone implants is one of the most common procedures performed by plastic surgeons around the world. Capsular contracture is one of the complication in breast augmentation that requires invasive reparation surgery. The inflammatory response to the breast implants appears to be directly associated with capsular contracture. In addition to the type of material (saline vs. silicone) used and it’s texture (smooth vs. textured), a number of factors were detected related to their position and the existence of a history of radiotherapy after cancer treatment for breast cancer. It tries to identify ideal methods to prevent and minimize the risk of developing capsular contracture. Among the methods currently used were described: placement of the implant in the retropectoral plane, dissection of a larger pocket, performing a rigorous hemostasis, use of implants with textured surface, minimizing the exposure time, contact and handling of the implant, irrigation of the pocket with antiseptic solutions (5% betadine) or broad-spectrum antibiotic solution to prevent the infectious process, the use of talc-free gloves, the use of corticosteroids, immuno-modulators and anti-inflammatory drugs.

A conservative treatment for chronic obstructive sialoadenitis by intraductal instillation of mucolytic, steroids and antibiotic solution

Purposes Reporting our experience in treating chronic obstructive sialadenitis with a protocol consisting of sialoendoscopy and intraductal instillation of antibiotics, steroids and n-acetyl-cysteine (NAC) solution. Methods Prospective study of patients with chronic obstructive sialadenitis with no apparent lithiasic obstructions, with recurrent non-lithiasic sialoadenitis and patients with lithiasic sialoadenitis not solved with sialoendoscopy. In all cases, a sialoendoscopy was performed. All the patients affected by lithiasic sialoadenitis where the chronic inflammation was resolved with sialoendoscopy were excluded from the study. The mid-term follow-up was performed at 12 months via phone interview, to understand whether patients had developed any further symptoms after the treatment. Results This study included 26 patients. All the patient without sialolithiasis have not reported any symptoms during the follow-up period. Two of those with sialolithiasis have not shown any signs of recurrence. The remaining three patients with non-resolved sialolithiasis had a recurrence of symptoms which were treated again with 1 intraductal administration of betamethasone, gentamicine and NAC, showing immediately a regression of the symptoms. Conclusions Intraductal administration of gentamicin + NAC + betamethasone seemed effective for the therapy of chronic obstructive sialoadenitis. Our protocol seemed effective also in that cases where it was not possible to remove or detect endoscopically an obstruction. In all these cases we have noticed an increase in the symptom-free time even in cases where it was not possible to remove the stones.

New method of salvage retinoblastoma treatment

Purpose. Elaboration of the new method of salvage retinoblastoma (RB) treatment, combining local and systemic chemotherapy. Material and methods. Salvage treatment using the new method was carried out in 71 children aged 2 months – 7 years on 102 eyes with RB in T1–T3 stages. At the Department of Pediatric Ophthalmopathology of SI «The Filatov Institute of Eye Diseases and Tissue Therapy of NAMS of Ukraine» the method of combined polychemotherapy (CPCT) was developed in 2010: primary IViC – injection of 0,01 µg (0,1 µg) Melphalan through pars plana; a course of CEV-protocol (drugs combination: Carboplatin + Etoposide Phosphate + Vincristine Sulfate) chemoreduction the next day after injection; monitoring the state of the tumor with repeated courses of SPHT every 3 weeks; addition of CPCT by focal destruction methods according to indications. In order to increase the ablasticity of IVi injections, we have developed the antireflux method of their implementation: to reduce IOP the diuretic injection is preliminarily performed in age-related dosage; puncture of the conjunctiva at the distance of 1–1,5 mm from the intended sclera puncture and its displacement above the IVi injection site; puncture of the sclera with obliquely perpendicular injection channel formation; IViC by cytostatic Melphalan in a volume of 0,1 ml in various dilutions depending on the indications; in repeated IViC – in different meridians; removing the needle with one-step tamponade of the injection site by cotton swab, antibiotic solution injecting under the conjunctiva with roller formation. Results. Ten-year experience of using the developed algorithm of salvage RB treatment by combined polychemotherapy, based on primary intravitreal melphalan chemotherapy (using the proposed antireflux injection method) with simultaneous systemic chemoreduction, proves its safety and effectivity – 77.5% regression of the tumors. Conclusion. Simultaneous action on the tumor of various cytostatics – one (melphalan) intraocular directly on the tumor and its vitreal clones, others – (carboplatin, etoposide, vincristine) – from the peripheral blood – creates the effect of «double blow» on RB cells. Key words: retinoblastoma, salvage treatment, combined polychemotherapy.

Comparison of the Sterilization Efficiency of 3 Disinfectants for Dropped Anterior Cruciate Ligament Grafts: A Systematic Review and Meta-analysis

Background: The inadvertent contamination of anterior cruciate ligament (ACL) grafts can occur if they are accidentally dropped on the floor during ACL reconstruction. There has been no meta-analysis conducted to compare the sterilization efficiency of the different disinfectants used on dropped ACL grafts. Purpose: To compare the sterilization efficiency of 3 disinfectants to decontaminate ACL grafts as necessary. Study Design: Systematic review. Methods: A systematic literature review was performed using the MEDLINE, Embase, and Cochrane Library databases. All studies reporting the management of dropped or contaminated grafts were considered for this meta-analysis. Results: A total of 7 studies meeting inclusion criteria were identified from a literature search. The pooled results of this meta-analysis indicated that the rate of positive cultures of ACL grafts dropped on the operating room floor was 44.9% and that the commonly contaminated microbes were staphylococci and bacilli. The meta-analysis results indicated that the sterilization efficiency of a 4% chlorhexidine solution was superior to an antibiotic solution (odds ratio [OR], 0.17 [95% CI, 0.05-0.57]; P = .004) and a 10% povidone-iodine solution (OR, 0.04 [95% CI, 0.01-0.20]; P < .0001). Further, the antibiotic solution was superior to the 10% povidone-iodine solution (OR, 0.20 [95% CI, 0.07-0.55]; P = .002). Conclusion: The results of our meta-analysis demonstrated that staphylococci and bacilli were the most common contaminants on dropped ACL grafts and that decontamination using a 4% chlorhexidine solution more reliably disinfected ACL grafts. This information can help to guide surgeons as regards appropriate remedial measures.

Heparin-mediated antibiotic delivery from an electrochemically-aligned collagen sheet

BACKGROUND: Implantable medical devices and hardware are prolific in medicine, but hardware associated infections remain a major issue. OBJECTIVE: To develop and evaluate a novel, biologic antimicrobial coating for medical implants. METHODS: Electrochemically compacted collagen sheets with and without crosslinked heparin were synthesized per protocol developed by our group. Sheets were incubated in antibiotic solution (gentamicin or moxifloxacin) overnight, and in vitro activity was assessed with five-day diffusion assays against Pseudomonas aeruginosa. Antibiotic release overtime from gentamicin infused sheets was determined using in vitro elution and high performance liquid chromatography (HPLC). RESULTS: Collagen-heparin-antibiotic sheets demonstrated larger growth inhibition zones against P. aeruginosa compared to collagen-antibiotic alone sheets. This activity persisted for five days and was not impacted by rinsing sheets prior to evaluation. Rinsed collagen-antibiotic sheets did not show any inhibition zones. Elution of gentamicin from collagen-heparin-gentamicin sheets was slow and remained above the minimal inhibitory concentration for gentamicin sensitive organisms for 29 days. Conversely, collagen-gentamicin sheets eluted their antibiotic payload within 24 hours. Overall, heparin associated sheets demonstrated larger inhibition zones against P. aeruginosa and prolonged elution profile via HPLC. CONCLUSION: We developed a novel, local antibiotic delivery system that could be used to coat medical implants/hardware in the future and reduce post-operative infections.

In Vitro Evaluation of Common Antimicrobial Solutions Used for Breast Implant Soaking and Breast Pocket Irrigation – Part 1: Efficacy Against Planktonic Bacteria

Background Planktonic bacteria can be inadvertently introduced during breast surgery procedures, which are hypothesized to lead to complications such as infection, capsular contracture, BIA-ALCL, and a prolonged local inflammatory response. The use of antimicrobial solutions such as triple antibiotic solution (TAB) and/or 10% povidone-iodine (PI), in breast pocket irrigation or implant soaking have been proposed to reduce planktonic bacterial attachment and potential complications. Objectives A series of in vitro assessments were performed to evaluate the antimicrobial utility of triple antibiotic solution (TAB) and PI, either alone or in combination, against planktonic bacteria. Methods Planktonic gram-positive and gram-negative bacterial strains were exposed to TAB and PI +/- TAB for up to 10 minutes in a bacterial time-kill assay. Efficacy of various dilutions of PI as well as the effects of serum protein on PI efficacy were also investigated. Results TAB was ineffective at the timeframes tested (≤ 10 minutes) when used alone; however, when used with PI, significant log reduction of all tested planktonic species was achieved. PI alone was also effective, even including dilute concentrations (e.g., 0.5% PI), although the presence of serum proteins required higher concentrations of PI (e.g., 2.5%) to eradicate the bacterial load. Conclusions Our data suggest PI-containing solutions may be preferred over either saline or TAB without PI for primary breast pocket irrigation and implant soaking in primary breast surgeries as a means to significantly reduce planktonic bacteria. These data provide an impetus for surgeons to re-evaluate the efficacy of TAB solution in these clinical settings.