Organic vs. Inorganic Tracheobronchial Airway Foreign Body Aspiration: Does Type/Duration Matter?

OBJECTIVE: We sought to determine the time course of clinical and histologic differences between aspirated inorganic and organic foreign bodies. STUDY DESIGN: In-vivo. METHODS: Twenty Sinclair miniature swine (Sus scrofa domesticus) were divided into two groups-inorganic or organic foreign bodies. Either an organic (peanut) or an inorganic (Lego) foreign body was placed within a bronchus and left for 3, 5, 7, 14 or 21 days. The airway was reassessed at the predetermined endpoint at which time endoscopic, gross, and histopathological findings were documented. Specimens were scored with a pathologic scoring system to assess injury severity from the foreign body. RESULTS: Foreign bodies were successfully placed in all 20 swine. Two animals required early euthanasia due to respiratory compromise. The foreign body was identified grossly in eight (40%) animals. An additional three (15%) had microscopic evidence suggestive of a previous foreign body of an undetermined duration. There was no difference in injury severity between organic and inorganic foreign bodies. The 3-day group had injuries limited to the bronchial lining, whereas the longer duration groups had bronchial and adjacent lung parenchymal involvement. There was no difference in injury severity between days 5 and 21. CONCLUSIONS: Airway foreign bodies initially cause bronchial damage. After 5 days, the foreign body causes lung parenchymal changes. There was no difference in airway lesion severity between organic and inorganic foreign bodies. LEVEL OF EVIDENCE: N/A Laryngoscope, 131:490-495, 2021.

Duration of Ureteral Stenting Following Ureteroscopic Perforation in a Porcine Model.

Objectives: Ureteroscopic ureteral perforations have been reported in up to 6% of cases, with recent studies suggesting a decline to less than 2%. Ureteroscopic perforations are managed with prolonged ureteral stenting of up to 6 weeks based on historical data. We sought to evaluate the time of urothelial healing and duration of ureteral stenting following a ureteroscopic perforation in a porcine model. Materials and Methods: Part A: Ureteral perforation using a semirigid ureteroscope was performed in 37 ureters. The ureters were stented using 4.7F × 22 cm stents for 3, 7, 10, or 14 days, and retrograde pyelograms performed after stent removal. Injured ureteral segments were collected for histologic evaluation. Part B: 8 ureters had endoscopic perforation and stenting for 7 days and then survived for 4 weeks for evaluation of urinary extravasation or hydronephrosis and histologic evaluation. Results: Part A: At 3 days of ureteral stenting, there was urinary extravasation on retrograde pyelograms and gross defect in all ureters; average creatinine increased (1.55-1.75 mg/dL). Starting at 7 days, no evidence of gross urothelial defects or extravasation, and average creatinine was stable. Histologic evaluation revealed urothelial healing by 7 days with ongoing tissue healing. Granulation tissue predominated in early phase of healing. Part B: With only 7 days of ureteral stenting, no extravasation or hydronephrosis developed a month after stent removal. Conclusions: Following ureteroscopic ureteral perforation in a porcine model, the urothelium is functionally intact with 7 days of stenting. These results are sustained without complications for at least 4 weeks after stent removal. While further studies are warranted, these results challenge the current practice of maintaining ureteral stenting for several weeks following ureteral perforation during ureteroscopy.

Laryngeal Thermal Injury Model.

A lack of reliable laryngeal thermal injury models precludes laryngeal burn wound healing studies and investigation of novel therapeutics. We hypothesize that a swine laryngeal burn model can allow for laryngeal burn evaluation over time. Twelve Yorkshire crossbreed swine underwent tracheostomy and endoscopically directed laryngeal burns using heated air (150-160°C). Swine larynges were evaluated and sectioned/stained at 12 hours, 1, 3, 7, 14, and 21 days. A board-certified veterinary pathologist assessed anatomic regions (left and right: epiglottis, true/false vocal folds, and subglottis) using a nine criteria histological injury scoring scale. Six swine were euthanized at scheduled endpoints, three prematurely (airway concerns), and three succumbed to airway complications after 16 to 36 hours. Endoscopic and gross examination from scheduled endpoints revealed massive supraglottic edema and tissue damage, particularly around the arytenoids, extending transglottically. Swine from premature endpoints had comparatively increased edema throughout. Microscopic evaluation documented an inverse relationship between injury severity score and time from injury. Inflammation severity decreased over time, nearly resolving by 14 days. Neutrophils predominated early with histiocytes appearing at 3 days. Granulation tissue appeared at 3 days, and early epiglottic and/or subglottic fibrosis appeared by 7 days and matured by 14 days. Edema, abundant initially, decreased by day 3 and resolved by day 7. This approach is the first to provide longitudinal analysis of laryngeal thermal injuries, reflecting some of the first temporal wound healing characteristic data in laryngeal thermal injuries and providing a platform for future therapeutic studies.

Non-human Primate Total-body Irradiation Model with Limited and Full Medical Supportive Care Including Filgrastim for Biodosimetry and Injury Assessment.

An assessment of multiple biomarkers from radiation casualties undergoing limited- or full-supportive care including treatment with filgrastim is critical to develop rapid and effective diagnostic triage strategies. The efficacy of filgrastim with full-supportive care was compared with results with limited-supportive care by analyzing survival, necropsy, histopathology and serial blood samples for hematological, serum chemistry and protein profiles in a non-human primate (Macaca mulatta, male and female) model during 60-d post-monitoring period following sham- and total-body irradiation with 6.5 Gy 60Co gamma-rays at 0.6 Gy min-1 Filgrastim (10 µg kg-1) was administered beginning on Day 1 post-exposure and continued daily until neutrophil counts were ≥2,000 µL-1 for two consecutive days. Filgrastim and full-supportive care significantly decreased the pancytopenia duration and resulted in improved animal survival and recovery compared to animals with a limited-supportive care. These findings also identified and validated a multiparametric biomarker panel to support radiation diagnostic device development.

Cercopithecine Herpesvirus 9 (Simian Varicella Virus) Infection after Total-Body Irradiation in a Rhesus Macaque (Macaca mulatta).

This case report describes a rhesus macaque (Macaca mulatta; male; age, 5 y; weight, 6.7 kg) with anorexia, dehydration, lethargy, ataxia, and generalized skin rashes that occurred 30 d after total-body irradiation at 6.5 Gy ((60)Co γ-rays). Physical examination revealed pale mucus membranes, a capillary refill time of 4 s, heart rate of 180 bpm. and respirations at 50 breaths per minute. Diffuse multifocal maculopapulovesicular rashes were present on the body, including mucocutaneous junctions. The CBC analysis revealed a Hct of 48%, RBC count of 6.2 × 10(6)/µL, platelet count of 44 × 10(3)/µL, and WBC count of 25 × 10(3)/µL of WBC. The macaque was euthanized in light of a grave prognosis. Gross examination revealed white foci on the liver, multifocal generalized petechiation on serosal and mucosal surfaces of the gastrointestinal tract, hemorrhagic lymph nodes, and hemorrhagic fluid in the thoracic cavity. Microscopic examination revealed cutaneous vesicular lesions with intranuclear eosinophilic viral inclusions within the epithelial cells, consistent with herpesvirus. Immunohistochemistry was positive for herpesvirus. The serum sample was negative for antibodies against Macacine herpesvirus 1 and Cercopithecine herpesvirus 9 (simian varicella virus, SVV). Samples submitted for PCR-based identification of the etiologic agent confirmed the presence of SVV DNA. PCR analysis, immunohistochemistry, and histology confirmed that lesions were attributed to an active SVV infection in this macaque. This case illustrates the importance of screening for SVV in rhesus macaques, especially those used in studies that involve immunosuppressive procedures.

Hemorrhage Exacerbates Radiation Effects on Survival, Leukocytopenia, Thrombopenia, Erythropenia, Bone Marrow Cell Depletion and Hematopoiesis, and Inflammation-Associated microRNAs Expression in Kidney.

Exposure to high-dose radiation results in detrimental effects on survival. The effects of combined trauma, such as radiation in combination with hemorrhage, the typical injury of victims exposed to a radiation blast, on survival and hematopoietic effects have yet to be understood. The purpose of this study was to evaluate the effects of radiation injury (RI) combined with hemorrhage (i.e., combined injury, CI) on survival and hematopoietic effects, and to investigate whether hemorrhage (Hemo) enhanced RI-induced mortality and hematopoietic syndrome. Male CD2F1 mice (10 weeks old) were given one single exposure of γ- radiation (60Co) at various doses (0.6 Gy/min). Within 2 hr after RI, animals under anesthesia were bled 0% (Sham) or 20% (Hemo) of total blood volume via the submandibular vein. In these mice, Hemo reduced the LD50/30 for 30-day survival from 9.1 Gy (RI) to 8.75 Gy (CI) with a DMF of 1.046. RI resulted in leukocytopenia, thrombopenia, erythropenia, and bone marrow cell depletion, but decreased the caspase-3 activation response. RI increased IL-1ß, IL-6, IL-17A, and TNF-α concentrations in serum, bone marrow, ileum, spleen, and kidney. Some of these adverse alterations were magnified by CI. Erythropoietin production was increased in kidney and blood more after CI than RI. Furthermore, CI altered the global miRNAs expression in kidney and the ingenuity pathway analysis showed that miRNAs viz., let-7e, miR-30e and miR-29b that were associated with hematopoiesis and inflammation. This study provides preliminary evidence that non-lethal Hemo exacerbates RI-induced mortality and cell losses associated with high-dose γ-radiation. We identified some of the initial changes occurring due to CI which may have facilitated in worsening the injury and hampering the recovery of animals ultimately resulting in higher mortality.

Laparoscopic colpotomy using monopolar electrocautery: does power really matter?

OBJECTIVE: The purpose of this study was to assess the extent and rate of vaginal tissue injury associated with the utilization of various monopolar electrosurgical power settings when laparoscopically transecting vaginal tissue. METHODS: This is an Institutional Animal Care and Use Committee-approved prospective, paired, single-blinded study. Externalized porcine vagina was transected using monopolar energy at 30, 50, and 80 W in the cut mode with laparoscopic Endo Shears. The slides were prepared and stained with both hematoxylin-eosin and Masson trichrome and were examined by board-certified veterinary pathologists blinded to the study. RESULTS: There were 18 swine; each animal was tested on all 3 power settings (n = 54). Tissue injury was measured to a mean (SD) of 767 (519) µm at 30 W, 690 (600) µm at 50 W, and 556 (470) µm at 80 W. When comparing the monopolar settings, the results were as follows: 30 versus 50 W (P = 0.33), 30 versus 80 W (P = 0.067), and 50 versus 80 W (P = 0.17). The mean (SD) time for complete transection was measured at each power setting (n = 18), with 35.8 (5.4) seconds for 30 W, 13.5 (5.5) seconds for 50 W, and 8.4 (5.1) seconds for 80 W (P < 0.001). There was a statistically significant difference in the mean (SD) rates of injury, with 20.8 (8.8) µm/s at 30 W, 39.8 (11.8) µm/s at 50 W, and 50.1 (19.2) µm/s at 80 W (P = 0.01). CONCLUSIONS: Using various power settings of monopolar energy may not make a significant difference in swine vaginal tissue damage at the time of colpotomy. However, there was a significant difference in the times and rates at which tissue was transected when using higher powers. We recommend using the 50- or 80-W setting, as this will likely decrease surgical times without altering vaginal tissue damage.

Effect of teriparatide [rhPTH(1,34)] and calcitonin on intertransverse process fusion in a rabbit model.

STUDY DESIGN: Randomized, double-blinded, placebo controlled animal study. OBJECTIVE: To evaluate the effect of teriparatide and calcitonin after an intertransverse process spinal fusion in a rabbit model. SUMMARY OF BACKGROUND DATA: It is widely recognized that some osteoporosis medications, including bisphosphonates, can interfere with bone healing. Although prescribed frequently in the treatment of osteoporosis, the effect of teriparatide and calcitonin on spinal fusion has not been fully elucidated. We hypothesized that teriparatide, being the only anabolic medication for osteoporosis treatment, would have a beneficial effect on spine fusion. METHODS: Fifty-one New Zealand white rabbits underwent a posterolateral L5-L6 intertransverse process arthrodesis using autogenous iliac crest bone graft. The rabbits were randomly divided into 3 groups. All animals received daily subcutaneous injections of group I (n = 17) 1 mL of saline placebo; group II (n = 17) 10 microg/kg/day of teriparatide; group III (n = 17) 14 IU/animal of calcitonin during the 8-week postoperative period. Postmortem analyses included manual palpation, radiographic, biomechanical, and histologic assessment. Three random 10x fields were examined/graded within the cephalad, middle, and caudal regions of each section (810 fields). Fusion quality was graded using the Emery histologic scale (0-7 based on fibrous/bone content of the fusion mass). RESULTS: Histologic fusion rates for teriparatide averaged 86.7% and was significantly greater than the autograft control group (50%) (P = 0.033). Radiographically, there was a strong trend towards teriparatide being superior to the calcitonin group (85.7% vs. 56.3%, respectively; P = 0.07). The average Emery grading score was 5.99 +/- 1.46 SD for the autologous group and 6.26 +/- 0.93 SD for the teriparatide group (P = 0.031). Although not significant, the teriparatide group showed less motion in flexion/extension, lateral bending, and axial rotation. CONCLUSION: Our results suggest that teriparatide enhances spinal fusion while calcitonin has a neutral effect. The teriparatide group had the best histologic fusion rate and Emery scores, while the calcitonin group was similar to the saline controls. Although not significant, the teriparatide group had a strong trend towards superior radiographic fusion over the calcitonin group.