Thermal Effects of Monopolar Electrocautery on Cartilage.

Grisel syndrome is a nontraumatic atlantoaxial subluxation after an inflammatory process in the upper cervical region. It results from a peripharyngeal infection as well as a rare complication following adenotonsillectomy. After the introduction of monopolar suction electrocautery in adenoidectomy, an increased incidence of Grisel's syndrome has been observed. The purpose of the study was to evaluate monopolar suction electrocautery as a possible risk factor. Retrospective chart review along with current measurements of monopolar and bipolar electrocautery during adenoidectomy. The charts of 1431 consecutive cases of adenoidectomy were reviewed before (n = 710) and after (n = 721) the introduction of monopolar suction electrocautery for intraoperative hemostasis. Moreover, energy of delivered current of electrocautery was measured in 30 pediatric patients during adenoidectomy. Three cases of Grisel's syndrome occurred as a postoperative complication in 721 adenoidectomies (0.4%) after the introduction of monopolar suction electrocautery. In contrast, no Grisel's syndrome was observed in 710 procedures before the use of monopolar electrocautery. Current measurements demonstrate an almost fourfold higher level of electrical energy using monopolar electrocautery compared with bipolar coagulation for bleeding control in adenoidectomy. Monopolar suction cautery in adenoidectomy may be considered as a risk factor for Grisel's syndrome.

Electrosurgical devices are widely used in penile surgery for hemostasis and tissue dissection. However, the neurovascular risks associated with monopolar electrocautery, particularly in the context of pelvic innervation and vascular supply, remain unclear. This study investigates the histopathological effects of monopolar versus bipolar electrocautery on pudendal ganglia and prostatic arteries in an experimental model. Seventeen male New Zealand rabbits were randomly assigned to three groups: Group I (control, surgical dissection = 5), Group II (bipolar electrocautery = 5), and Group III (monopolar electrocautery = 7). A standardized preputial incision was performed. After a 3-week follow-up, pudendal ganglia and prostatic arteries were excised and analyzed. Degenerated neuron density (DND) and vasospasm index (VSI) were evaluated stereologically. The relatively small sample size (n = 17) represents a methodological limitation and may affect the generalizability of the findings. Quantitative analyses revealed significantly higher DND and VSI in the monopolar group (DND: 198 ± 37 neurons/mm³; VSI: 2.234 ± 0.987), compared to the bipolar (DND: 31 ± 6; VSI: 1.197 ± 0.120) and control groups (DND: 9 ± 3; VSI: 1.034 ± 0.036), with all comparisons showing statistical significance (p < 0.001). These findings indicate progressive neurovascular injury, most pronounced with monopolar electrocautery. Monopolar electrocautery during penile surgery induces marked neurovascular injury, potentially impairing pelvic nerve function and vascular regulation. Bipolar cautery is associated with a safer histological profile and should be preferred. Future research should include molecular, functional, and long-term outcome assessments.

Ethylene-vinyl alcohol copolymer mixed with micronized tantalum (Ta) as radiopacifier (Onyx; Micro Therapeutics Inc., Irvine, CA) has emerged as a useful liquid embolic agent for vascular malformations. We describe intraoperative ignition of Onyx-embolized tissue and undertake an in vitro investigation to reproduce and characterize this hazard. Samples of Onyx, Ta-depleted Onyx, Ta-n-butylcyanoacrylate (Ta-NBCA), and Ta powder were exposed to monopolar and bipolar electrocautery in cut and coagulation modes at different power settings to reproduce the intraoperative findings. Recordings of sparking and combustion events were analyzed to characterize duration and relative frequency. Spark showers and self-sustained combustion were observed intraoperatively when an Onyx-embolized artery was coagulated with the monopolar electrocautery. Sparking covered a radius greater than 10 cm, and combustion lasted a median of 1.65 seconds (range, 0.3-12.3 s). Sparking and sustained combustion were reproduced in vitro by both cut and coagulation monopolar modes in Onyx casts and free Ta powder but not in samples of Ta-depleted Onyx or casts of Ta-NBCA. Ignition was similarly observed when using bipolar electrocautery but only at higher energy settings. Electrocautery use on tissue containing Onyx results in potentially dangerous uncontrolled sparking and combustion in a process that is Ta dependent. It is recommended that Ta-NBCA be used instead of Onyx in situations mandating the use of a liquid embolic and high-energy electrocautery, pending the development of a safer radiopacifier for use with ethylene-vinyl alcohol copolymer.

Lasers have been shown to cause permanent shape change in cartilage via photothermally induced mechanical stress relaxation. While the biophysical properties of cartilage during laser irradiation have been studied, tissue viability following laser irradiation has not been fully characterized. In this study, cell viability staining and flow cytometry were used to determine chondrocyte viability following photothermal stress relaxation. Porcine septal cartilage slabs (10 X 25 X 1.5 mm) were irradiated with light from a Nd:YAG laser ((lambda) equals 1.32 micrometer, 25 W/cm<SUP>2</SUP>) while surface temperature, stress relaxation, and diffuse reflectance were recorded. Each slab received one, two, or three laser exposures (respective exposure times of 6.7, 7.2, 10 s), determined from measurements of diffuse reflectance, which correlate with mechanical stress relaxation. Irradiated samples were then divided into two groups analyzed immediately and at five days following laser exposure (the latter group was maintained in culture). Chondrocytes were isolated following serial enzymatic digestion with hyaluronidase, protease, and collagenase II for a total of 17 hours. Chondrocytes were then stained using SYTO<SUP>R</SUP>/DEAD Red<SUP>TM</SUP> (Molecular Probes; Eugene, OR) wherein live cells stained green (530 nm) and dead cells stained red (630 nm) when excited at 488 nm. A flow cytometer (FACScan, Becton Dickinson, Franklin Lakes, NJ) was then used to detect differential cell fluorescence; size; granularity; and the number of live cells, dead cells, and post irradiation debris in each treatment population. Nearly 60% of chondrocytes from reshaped cartilage samples isolated shortly after irradiation, were viable as determined using flow cytometry while non- irradiated controls were 100 percent viable. Specimens irradiated two or three times with the laser demonstrated increasing amounts of cellular debris along with a reduction in chondrocyte viability: 31 percent following two laser exposures, and 16 percent after three laser exposures. In those samples maintained in culture medium and assayed 5 days after irradiation, viability was reduced by 28 to 88 percent, with the least amount of deterioration in untreated and singly irradiated samples. Functional fluorescent dyes combined with flow cytometric analysis successfully determines the effect of laser irradiation on the viability of reshaped cartilage. The flow cytometric approach to viability is accurate, fast, and can handle large sample numbers and sizes. Most importantly, since the method reveals that a single laser exposure of 6.7 s (sufficient for sustained shape change) causes less than 40 percent acute reduction in viability, photothermal reshaping of cartilage may be further researched as a clinical alternative to conventional techniques.

Quantitation of colonic injury from argon laser, neodymium: YAG laser and monopolar electrocautery applied to flat mucosa and small sessile polyps of the canine colon

Cartilage damage is frequently observed in advanced destructive gout. The aim of our study was to investigate the effects of monosodium urate monohydrate (MSU) crystals on chondrocyte viability and function. The alamarBlue assay and flow cytometry were used to assess the viability of primary human chondrocytes and cartilage explants following culture with MSU crystals. The number of dead chondrocytes in cartilage explants cultured with MSU crystals was quantified. Real-time PCR was used to determine changes in the relative mRNA expression levels of chondrocytic genes. The histological appearance of cartilage in joints affected by gout was also examined. MSU crystals rapidly reduced primary human chondrocyte and cartilage explant viability in a dose-dependent manner (p < 0.01 for both). Cartilage explants cultured with MSU crystals had a greater percentage of dead chondrocytes at the articular surface compared to untreated cartilage (p = 0.004). Relative mRNA expression of type II collagen and the cartilage matrix proteins aggrecan and versican was decreased in chondrocytes following culture with MSU crystals (p < 0.05 for all). However, expression of the degradative enzymes ADAMTS4 and ADAMTS5 was increased (p < 0.05 for both). In joints affected by gout, normal cartilage architecture was lost, with empty chondrocyte lacunae observed. MSU crystals have profound inhibitory effects on chondrocyte viability and function. Interactions between MSU crystals and chondrocytes may contribute to cartilage damage in gout through reduction of chondrocyte viability and promotion of a catabolic state.

To compare the effects of Tsmu solution with vitrification on chondrocyte viability and examine histological and biomechanical properties of osteochondral allografts (OCAs) after storage, OCAs from femoral condyles of New Zealand rabbits were harvested, stored for 35days in Tsmu solution or by in vitro vitrification, and subjected to in vivo and in vitro assays. Stored OCAs were transplanted into knee femoral condyle cartilage defects in recipient rabbits. Chondrocyte viability and histological changes of cartilage grafts were assessed in vitro. Gross assessment, chondrocyte viability, histological assessment, OCA biomechanics, and immunological markers were evaluated in vivo 6months after transplantation. Fresh OCAs served as in vitro and in vivo controls. Chondrocyte viability and scores for cartilage surface and histological quantitative assessment were superior for Tsmu solution compared with vitrification, but inferior compared with fresh OCAs in vitro and in vivo. With the exception of interleukin 6 content, biomechanical features of samples stored in Tsmu solution were superior to vitrification, and inferior to fresh OCAs in vivo. Thus, Tsmu solution provided suitable storage that improved chondrocyte viability, intact OCA cartilage matrix architecture, and transplantation outcomes.

According to the principles of modern functional nasal surgery, the ideal technique for the surgical management of inferior nasal turbinate (INT) hypertrophy should strike a balance between optimal volume reduction and preservation of mucosa functions, especially that of mucociliary clearance.The aim of the present thesis was to investigate histological changes and wound healing process of INT mucosa after submucosal tissue volume reduction using ultrasound (US) energy, radiofrequency (RF) energy and monopolar electrocautery (MEC). Our secondary goal was to estimate the suitability of the sheep as an experimental model for the exploration of INT mucosa wound healing postoperatively.We conducted a prospective, comparative, randomized, blinded and controlled trial, based on experimental protocol in a sheep model. Twenty three animals were included in the study. INTs of 18 animals were subjected to submucosal coagulation using US, RF or MEC (n = 12 INTs per method). One, three or eight weeks postoperatively, INTs were totally removed in order to be studied histologically (n = 4 INTs per time point for each method applied). The control group (CG) consisted of 5 animals (n = 10 INTs) representing the preoperative histological picture of INT mucosa. After the application of hematoxylin - eosin staining, five basic parameters were estimated, stromal fibrosis, submucosal edema, engorgement of venous sinusoids, inflammation reaction and epithelial cell necrosis. Histological grading of the changes was performed semi - quantitatively using a 4-point scale (0 = absence, 1 = mild, 2 = moderate, 3 = pronounced). Statistical analysis of the data was performed.US - group revealed pronounced fibrosis (Median Value (MV) = 3), impressive reduction of stromal edema and evident reduction of venous sinusoids’ engorgement (p &lt; 0.001, p &lt; 0.001 and p = 0.058, compared with CG, respectively) by the end of the 1st postoperative week already. Severe inflammation reaction, which was present in the primary phase, declined rapidly, approaching the preoperative picture by the end of 3rd week (p = 0.070). Relatively limited areas of partial epithelial necrosis were initially observed. Thereinafter, the degree of necrosis became extremely low, getting close to normal 3 weeks postoperatively (p = 1). In the RF - treated group, fibrosis became severe enough (MV = 2.5), while edema and venous sinusoids’ engorgement were considerably decreased compared with CG (p = 0.074 and p = 0.008 respectively) by the end of 3rd postoperative week. Inflammation resolved and epithelial necrosis restored 8 weeks after surgery (p = 0.356 and p = 1, vs CG, respectively). Additionally, in all postoperative cases a well-defined intact basement membrane was present across the US and RF - treated areas. In MEC - group, fibrosis, acute inflammation reaction and epithelial necrosis presented an obviously instable progression between samples of different time points. Moreover, 8 weeks postoperatively, we observed relatively poor degree of fibrosis (MV = 1.5), marked inflammation and pronounced congestion of venous sinusoids, with significantly different values compared with the parameters found in US-group and RF-group at the same time point (p = 0.061, p &lt; 0.05 and p &lt; 0.05 respectively), along with a notable degree of epithelial necrosis compared with CG (p = 0.020). Furthermore, the method failed to diminish significantly the congestion of INT erectile tissue regardless of the time point studied (p ≥ 0.236 vs CG). Occasionally, the continuity of the basement membrane was focally disrupted.In conclusion, submucosal coagulation of INT using US and RF energy could establish significant and stable shrinkage of the turbinate, while providing regular rapid wound healing and respect to the epithelium, parameters that justify a minimally invasive behavior. MEC may be considered as an insecure choice, since it reveals questionable and unpredictable ability in alleviating nasal obstruction caused by INT hypertrophy along with delayed wound healing process and potential noxious effect on turbinate epithelium. Finally, the sheep seems to be a suitable model for the histological study of INT wound healing following surgical manipulations.

Background Because chondrocytes are responsible for articular cartilage matrix synthesis and maintenance, reduced chondrocyte viability could compromise graft survival, healing, and clinical outcome. Hypothesis Typical forces used in osteochondral grafting reduce the viability of the chondrocytes in the graft. Study Design: Controlled laboratory study. Methods Osteochondral grafting was performed in 4 fresh-frozen cadaver knees (n = 16 per knee). Impact force was measured during extrusion of the donor graft from the harvester into the recipient site, seating the graft flush with the articular surface of the surrounding cartilage using a tamp, and recessing the graft surface below the recipient articular surface. The magnitudes of forces measured during cadaver surgery (200,400, and 800 N) were reproduced using a drop-tower apparatus on 80 fresh osteochondral grafts harvested from knee blocks provided by tissue banks. Cell viability and glycosaminoglycan release in media were measured at 48 hours after injury. Results Forces were relatively low (range, 124-356 N) during graft extrusion from the harvester into the recipient defect or during flush seating (range, 191-418 N) of the graft. Attempts to recess the graft generated significantly greater force (range, 147-685- P < .01). When the donor graft length was 2 mm longer than the depth of the recipient hole, the mean impact force generated was even higher (range, 240-1114 N) than the force seen in a donor graft of equal length. No reduction in viability was seen at 200-N and 400-N impacts. However, a significant decrease in chondrocyte viability was seen in the group impacted with 800 N (only 50% of cells were viable, compared with 91 % in the sham group; P < .01). Glycosaminoglycan levels in culture media did not correlate significantly with insertion force. Conclusion Typical graft insertion forces did not significantly reduce chondrocyte viability. However, increased graft length relative to the depth of the recipient hole and attempts to recess the graft generated higher forces, which reduced chondrocyte viability. Clinical Relevance Any theoretical benefits of cancellous bone compaction that may occur in grafts that are recessed or are longer than the recipient holes must be balanced against the potential reduction in chondrocyte viability.

ObjectivesThe present study was designed to compare the graft resorption characteristics of autogenous cartilage from the septum, auricle, and costal in the superficial muscular aponeurotic system of the nasal dorsum of the rabbit model.MethodsEqual-sized perichondrium-free septal, auricular, and costal cartilage grafts were collected from fifteen New Zealand white rabbits. Cartilage grafts were taken at the scale of two grafts from each animal’s ear, two from its costal part, and one from its septum. Costal cartilage grafts that were shaped with a micro-motor device and monopolar electrocautery, elastic cartilage grafts that were shaped with a micro-motor device and monopolar electrocautery, and septal cartilage grafts that were shaped with a scalpel were all implanted into the dorsum of rabbit’s noses to create five groups. All autogenous cartilage tissues were removed 3 months later. Cartilages were evaluated for histological features, graft mass, and chondrocyte density resorption.ResultsThe elastic cartilage group, where electrocautery was used to shape the cartilage, had a higher resorption score than the other groups. The costal cartilage graft shaped with a micro-motor was also observed to have the best cartilage regeneration score.ConclusionWe observed that the resorption of costal cartilage was lower than that of ear and septum cartilage. It was determined that micro-motor application for the shaping process caused less resorption and stimulated more regeneration than cautery application.Level of Evidence IIIThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Background: Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine. Study Design: Controlled laboratory study. Methods: Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination. Results: Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups (P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability. Conclusion: Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability. Clinical Relevance: This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

Background: Insertion force has been shown to significantly reduce chondrocyte viability during osteochondral allograft transplantation. How graft size influences the required insertion force and chondrocyte viability has yet to be determined. Hypothesis/Purpose: The purpose was to characterize how graft size influences insertion force requirements and chondrocyte viability during osteochondral transplantation. The hypothesis was that larger grafts would require greater force and reduce chondrocyte viability. Study Design: Controlled laboratory study. Methods: Four graft sizes—15 × 5 mm, 15 × 10 mm, 25 × 5 mm, and 25 × 10 mm (diameter × depth)—were harvested from 13 thawed fresh-frozen human cadaveric distal femurs. Average, maximum, and cumulative force and number of impacts were recorded for 44 grafts by a surgical mallet embedded with a calibrated force sensor. In a separate experiment, fresh osteochondral tissues were subjected to mechanical loading. To capture a range of clinically important forces, categories were selected to correspond to impaction force data. Chondrocyte viability was assessed with confocal laser microscopy and live/dead staining. Results: Total force for all grafts averaged 4576 N. Median number of impacts for all grafts was 20 (range, 7-116). The mean number of impacts for 5-mm-deep grafts was 14.2 (95% CI, 10.8-18.6), as compared with 26.3 (95% CI, 19.9-34.4) for 10-mm-deep grafts (P < .001). The mean cumulative force for 5-mm-deep grafts was 2128 N (95% CI, 1467-3087), as opposed to 4689 N (95% CI, 3232-6803) for 10-mm-deep grafts (P = .001). For every 1 mm in graft depth, an average of 13.1% (95% CI, 6.2%-20.3%) more impacts are required when controlling for diameter and density (P < .001). For every 1 mm in graft depth, the force required increases on average by 17.1% (95% CI, 7.7%-27.4%) when controlling for diameter and density (P = .001). There was a significant reduction in chondrocyte viability for the forces required for graft thickness values >10 mm. Only forces associated with graft thickness <10 mm had chondrocyte viabilities consistently >70%. Conclusion: Insertion force increases significantly with increasing graft depth. Controlling for diameter and bone density, a 1-mm increase in graft depth is associated with 13.1% more impacts and 17.1% more force. Chondrocyte viability was significantly reduced to <70% at average forces associated with grafts thicker than 10 mm. Clinical Relevance: Based on the current data, graft depth is an important consideration for surgeons when sizing osteochondral allograft transplant for chondral lesions of the knee.

The development of infrared microspectroscopy techniques to examine the effect of monoclonal antibodies to type II collagen in a murine model of rheumatoid arthritis

A comparison of average daily gain, apparent digestibilities, energy balance, rumen fermentation parameters, and serum metabolites between yaks (Bos grunniens) and Qaidam cattle (Bos taurus) consuming diets differing in energy level

The dourado, Salminus brasiliensis, presents excellent farming characteristics, such as fast growth and excellent flesh quality. However, the lack of the knowledge on the species nutritional requirements and biological value of feedstuffs hamper the formulation of diets for optimized performance and, consequently, the species' intensive farming. To determine de species nutritional requirements, juveniles dourado (5.29 0.21 g) were stocked in 75 cages (60-L) set up in 1,000-L containers, and fed for 60 days diets containing levels of crude protein (CP) between 35 to 51% (4% increments) and gross energy (GE) varying of 4,200 to 5,000 kcal/kg feed (200 kcal increments). The trial was set up in a completely randomized design, 5 5 factorial scheme (five levels of GE and five levels of CP, with three replications). Data on weight gain (WG), percentage weight gain (PWG), daily feed consumption (DFC), food conversion ratio (FCR), specific growth rate (SGR) and nutrient retention were recorded. No interaction (P>0.05) between dietary energy and protein levels for all parameters was detected. The values of DFC, WG, RWG, FCR, SGR and nutrient retention were affected (P<0.05) by the dietary protein and energy levels. DFC decreased with increasing energy levels. The liposomatic and viscerosomatic indexes were affected (P<0.05) by dietary energy levels, and increased with increasing energy levels. Through broken line analysis technique, the requirements estimated for optimum performance and nutrient and energy retention of dourado were 45.08% CP, 4,600.0 kcal GE/kg, and a energy:protein ratio varying between 10.20 and 10.65 kcal of GE/g of CP. Apparent digestibility is one of the main tools to evaluate the potential of an ingredient to be used in aquafeeds. To evaluate the apparent digestibility coefficient (ADC) of energy and nutrients of animal and plant protein sources in practical diets for the dourado (19.49 5.04 g), fish were stocked in plastic cages (80-L) and fed pelleted test diets containing 30% of test ingredients plus 70% of a reference diet (RR) containing 48.14% CP, 4,453.2 kcal GE/kg, and 0.1% of chromium oxide III. After the last daily meal, cages were transferred to cylindrical conical-bottomed aquaria (200-L) where feces were collected by sedimentation in refrigerated containers. ADCs of nutrients and energy of selected protein sources differed (P<0.01); ADC values were: 94.25; 91.26; 93.05 and 93.47% for CP, 91.03; 90.33; 87.83 and 88.78% for GE, 92.06; 84.49; 80.58 and 79.25% for ash, 83.90; 80.26; 84.25 and 84.55% for dry matter, 97.38; 96.74; 93.32 and 91.46% for lipid for fish meal (FM), poultry by-product meal (PBM), soybean meal (SBM), and corn gluten meal (CGM), respectively. The average ADC of amino acids was: 93.60; 89.95; 92.07 and 92.45% of FM, PBM, SBM and CGM, respectively. All tested ingredients were efficiently used and can partially replace FM in diets for carnivorous dourado.