Does Endoscopic Transnasal Optic Nerve Decompression Followed by Radiosurgery Improve Outcomes in the Treatment of Parasellar Meningiomas?

INTRODUCTION: The clinical management of parasellar meningiomas (PM) is challenging due to their intimate association with critical neurovascular structures. Consensus regarding the recommended treatment protocol is lacking. This study will evaluate patients' visual outcomes following endoscopic transnasal optic nerve decompression (ETOND) and will investigate the possibility of reducing the rate of complications associated with stereotactic radiosurgery (SRS). METHODS: Retrospective analysis was conducted on all patients who underwent ETOND for PM between 2013 and 2020. The study comprised 12 patients (7 women and 5 men aged 36-75 years; mean, 55.2 years; median, 57.6 years) in which 14 optic nerve decompression procedures were carried out. Patients were followed up for 6 to 86 months (mean, 29.3 months; median, 25 months). There were five cases of spheno-orbital meningioma, four cases of cavernous sinus meningioma, and one case each of petro-clival meningioma, optic nerve sheath meningioma, and planum sphenoidale/tuberculum sellae meningioma. Visual outcome was evaluated and any postoperative complications noted. RESULTS: Improvements in visual acuity were noted in 10 of 14 eyes (71.4%) 3 to 6 months postoperation. Visual acuity remained stable in the remaining four eyes. No deterioration of visual acuity was noted during the follow-up period. In total, 9 of the 12 patients underwent SRS. No tumor growth was determined, while reduction in tumor volume was noted in five patients following SRS. No complications associated with SRS or the surgical procedure were noted. CONCLUSIONS: ETOND appears to be a promising technique for increasing rates of improved visual function, while reducing the risk of post SRS-related complications. In combination with subsequent SRS, it is an ideal treatment modality in the management of parasellar meningiomas. Confirmation of our findings would require a larger, prospective multicenter study.

Endoscopic two-port technique for orbital tumours: combined transnasal and sublabial approach.

INTRODUCTION: The aim of this study was to present the indications for a combined endoscopic transnasal and sublabial transantral approach for the surgical treatment of orbital lesions. MATERIAL AND METHODS: This case study enrolled 10 patients scheduled for endoscopic transnasal surgery for treating orbital lesions from 2009 to 2020. When the tumour was localised to the medial part of the orbit, patients underwent endoscopy with a transnasal mononostril approach. Alternatively, when the tumour was localised to the mediocaudal part of the orbit, and when instrument manoeuvreability was limited, the transnasal approach was combined with a sublabial transantral approach. Herein, we evaluate the indications, complications, and advantages of monoportal and combined two-portal approaches. RESULTS: 8/10 patients (80%) underwent surgery with the transnasal mononostril approach, and 2/10 (20%) underwent surgery with the combined transnasal mononostril and sublabial transantral approach. In the two latter cases, visualisation of the operation field was excellent, and there was adequate room for manipulating instruments. CONCLUSIONS: The combined mononostril-transantral approach provided the space necessary to manoeuvre instruments and to visualise the surgical field in treating mediocaudal orbital lesions. CLINICAL IMPLICATIONS: This two-portal approach enables extensive resections of intraconal lesions. It should be considered to be a suitable and safer alternative to the binostril approach.

[Retrobulbar Haematoma - a Complication that May Impair Vision]. / Das retrobulbäre Hämatom ­ eine potenziell visusbedrohende Komplikation.

Retrobulbar haematoma (RBH) is a rare complication that may affect vision after a trauma or a surgical procedure. The diagnosis must be made promptly, as only early surgical intervention can adequately prevent irreversible visual impairment. Because of the bony orbital walls, there is hardly any room for the increasing intraorbital volume due to the retrobulbar haemorrhage. This leads to an increase in intraorbital pressure and subsequently to compression of the optic nerve. Symptoms include disorders in ocular motility, ophthalmoplegia, diplopia, conjunctival chemosis, subconjunctival haemorrhage, proptosis, increased intraocular pressure, deterioration in visual acuity, decreased direct pupillary reflex, and a relative afferent pupillary defect. If the cause is traumatic or iatrogenic, prompt lateral canthotomy with cantholysis is the treatment of choice, and successfully lowers pressure in most cases. It can be performed in the emergency room by an ophthalmologist and may even be indicated without previous imaging. As the reconstruction of cantholysis is generally uncomplicated, we recommend performing the procedure when RBH is suspected. If canthotomy with cantholysis does not lead to adequate improvement, surgical orbital decompression must be performed. Supportive treatment should always include systemic steroids.

Endoscopic Transcaruncular Medial Orbitotomy as an Alternative Approach to Anterior Ethmoidal Artery Coagulation.

BACKGROUND: The authors present a series of 5 patients with anterior epistaxis in which a transcaruncular endoscopic approach was used for the anterior ethmoidal artery coagulation (AEA). METHODS: Six AEA coagulations (5 unilateral, 1 bilateral) using the transcaruncular endoscopic approach were performed in 5 patients with anterior epistaxis resistant to conservative measures. An incision was made between the plica semilunaris of conjunctiva and the lacrimal caruncle. Using a rigid endoscope, tissues were dissected lateral to the lacrimal sac, to the posterior lacrimal crest. The periorbit was incised and pulled aside. Hereafter, the technique was the same as that involving a frontoethmoidal incision. After bipolar coagulation of the AEA, the conjunctiva was sutured. RESULTS: Bleeding was resolved in all patients. One patient experienced early postoperative temporary diplopia. CONCLUSIONS: The transcaruncular endoscopic approach is a promising technique with no outer scarring. It is convenient in patients with difficult orientation in the nasal cavity, relatively safe, and faster than the transnasal endoscopic approach.

Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer.

PURPOSE: The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. PATIENTS AND MATERIALS: Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. RESULTS: Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. CONCLUSION: Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation.

Lacrimal sac dacryoliths (86 samples): chemical and mineralogic analyses.

BACKGROUND: Because dacryoliths occur at low frequency, few studies have focused on their composition. We aimed to present findings from morphological, chemical, and mineralogic analysis of 86 dacryoliths. METHODS: We studied 86 dacryoliths obtained during 832 dacryocystorhinostomies (DCR) performed for postsaccal obstruction. We examined the samples with atomic infrared spectrometry (80 samples), amino acid analysis (17 samples), scanning electron microscopy, and an electron microprobe with an energy dispersive detector (seven samples). RESULTS: Dacryoliths were found in 86/832 DCRs (10.3 %), mostly in patients with primary acquired nasolacrimal duct obstruction. All the dacryoliths were soft, composed of organic material, including proteins and mucoproteins, with approximately 20 % amino acid content. There were no "hard" dacryoliths composed of calcium phosphate. The stones were composed of lobes and lobules built on an amorphous core material with small cavities, probably as a result of various chemical processes that produced a gaseous product. The most frequent elements found in inorganic inclusions were silicon, magnesium, sulfur, potassium, calcium, sodium, and chlorine. Also, some particles had high contents of bismuth, titanium, iron, and organic fibers. The fibers found in the core of dacryoliths suggested a potential origin from cotton swabs used in cosmetics. CONCLUSION: Dacryoliths are composed almost exclusively of organic material, including proteins and mucoproteins, with approximately 20 % amino acid content.

Lacrimal sac dacryolith (76 cases): a predictive factor for successful endonasal dacryocystorhinostomy?

To evaluate whether the presence of dacryolith is a predictive factor for successful dacryocystorhinostomy. The success rate of endonasal dacryocystorhinostomy (EDCR) performed to relieve obstruction of the nasolacrimal duct was evaluated according to the presence of dacryolithiasis. The surgical results of patients with (group I) and without dacryoliths (group II) were analysed and compared 1-year post surgery. A total of 771 EDCRs performed from 1994 to 2010 were evaluated. Dacryolith was found in 76/771 procedures (9.9%). Complete improvement was achieved significantly more frequently in group I (76/76; 100.0%) than in group II (633/695; 91.1%; p < 0.001). EDCRs were performed significantly more frequently in people aged 31-50-years, the average age of the group I was 41.1 years (range 18-72 years), of the group II 53.3 years (range 3 months-86 years; p < 0.001). There was no significant difference in the female-to-male ratio in the two groups. The presence of dacryoliths is a predictive factor for successful endonasal dacryocystorhinostomy.

Squamous cell carcinoma antigen as a marker of sinonasal inverted papilloma.

This prospective study aimed to evaluate the usefulness of squamous cell carcinoma antigen (SCCA) as a clinical marker of sinonasal inverted papilloma (IP). The potential benefit of SCCA in the diagnosis of unilateral nasal pathology and as a marker of hidden recurrence was evaluated as well. Blood samples from patients with sinonasal IP were examined to determine serum SCCA levels before surgery, the day after surgery, and every 6 months during follow-up. Preoperative and postoperative levels of SCCA were compared. Twenty consecutive patients with histologically confirmed IP were included in the study, conducted between 2000 and 2011. The mean age of the patients was 54.2 years (range 35-72). The mean serum SCCA level before surgery was 3.885 µg/l (range 0.7-7.6). A decrease of the SCCA level to 0.885 µg/l (range 0.1-1.9) was observed on the 1 day after a radical surgical procedure. A statistically significant difference between the preoperative and postoperative levels was observed (P < 0.001). Elevated levels of SCCA during long-term follow-up were observed in three patients. All of them had a recurrence of IP. We conclude that the serum level of SCCA is a useful clinical marker of the presence of sinonasal IP. The level of SCC antigen was significantly lower in patients after IP was completely removed. According to our results, SCCA level also appears to be useful for long-term follow-up (hidden recurrence diagnosis).

Deep neck infections: risk factors for mediastinal extension.

The goal of the study was to find out the risk factors for the development of mediastinitis in patients with deep neck infections (DNI) and describe the differences in symptoms and clinical image between uncomplicated DNI and infections with mediastinal spread. Our study represents the retrospective analysis of 634 patients with DNI. The file was divided into two groups. There were 619 patients (97.6%) in the first group who had an uncomplicated course of DNI without spread of infection into mediastinum (DNI group). The second group included 15 patients (2.4%) with descending mediastinitis as a complication of DNI (mediastinitis group). The most frequent comorbidities were cardiac and pulmonary diseases, which were more frequent in the mediastinitis group comparing to DNI group. Dental origin of the infection was more frequent in DNI group than in the mediastinitis group. On the other hand, tonsillar origin of the infection was more frequent in the mediastinitis group than in DNI group. In both mediastinitis and DNI groups, the typical presenting symptoms were pain, oedema and dysphagia. Furthermore, dysphagia, dyspnoea, dysphonia and restriction of neck movements were more significant in the mediastinitis group than in DNI group. The incidence of airway obstruction, sepsis, pneumonia and death was significantly higher in the mediastinitis group than in DNI group. Due to our results, the predisposing factors for mediastinal extension of DNI are cardiovascular and pulmonary diseases. Mediastinitis is associated with higher morbidity and mortality than DNI. The most common complications are airway obstruction, pneumonia and sepsis.

High PD-L1 expression on immune cells along with increased density of tumor-infiltrating lymphocytes predicts a favorable survival outcome for patients with loco-regionally advanced head and neck cancer: early results from a prospective study.

Introduction: In the era of personalized medicine and treatment optimization, use of immune biomarkers holds promise for estimating the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) undergoing definitive treatment. Methods: To evaluate the prognostic potential of immune biomarkers, we conducted a prospective monocentric cohort study with loco-regionally advanced HNSCC patients indicated for definitive radiotherapy/radiochemotherapy at the Department of Oncology, Ostrava University Hospital, Czech Republic, between June 2020 and August 2023. We focused on the expression of programmed death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) relative to overall survival (OS) and specific survival rates. Associations between biomarkers and survival rates were assessed by crude and adjusted hazard ratios (cHR, aHR, respectively) obtained from Cox proportional hazards regression. Results: Among a total of 55 patients within a median follow-up of 19.7 months, there were 21 (38.2%) all-cause deaths and 15 (27.3%) cancer-related deaths. An overall survival (OS) rate of 61.8% and a disease-specific survival (DSS) rate of 72.7% were recorded. A significant association between survival rates and a ≥10% difference in PD-L1 expression on immune versus tumor cells (high PD-L1IC expression) was documented regardless of the type of analysis (univariate or multivariate). In addition, a stronger association was confirmed for OS and the composite biomarker high PD-L1IC expression along with either median-higher CD8+ TIL count or increased TIL density ≥30%, as indicated by an aHR of 0.08 (95% CI, 0.01 to 0.52) and 0.07 (95% CI, 0.01 to 0.46), respectively. Similar results were demonstrated for other specific survival rates. Discussion: The early outcomes of the present study suggest the utility of a strong prognostic factor involving a composite biomarker high PD-L1IC expression along with increased TIL density in HNSCC patients undergoing definitive radiotherapy and radiochemotherapy. Trial registration: The study is registered with Clinicaltrials.gov. - NCT05941676.

Arrival times by Recurrent Neural Network for induced seismic events from a permanent network.

We have developed a Recurrent Neural Network (RNN)-based phase picker for data obtained from a local seismic monitoring array specifically designated for induced seismicity analysis. The proposed algorithm was rigorously tested using real-world data from a network encompassing nine three-component stations. The algorithm is designed for multiple monitoring of repeated injection within the permanent array. For such an array, the RNN is initially trained on a foundational dataset, enabling the trained algorithm to accurately identify other induced events even if they occur in different regions of the array. Our RNN-based phase picker achieved an accuracy exceeding 80% for arrival time picking when compared to precise manual picking techniques. However, the event locations (based on the arrival picking) had to be further constrained to avoid false arrival picks. By utilizing these refined arrival times, we were able to locate seismic events and assess their magnitudes. The magnitudes of events processed automatically exhibited a discrepancy of up to 0.3 when juxtaposed with those derived from manual processing. Importantly, the efficacy of our results remains consistent irrespective of the specific training dataset employed, provided that the dataset originates from within the network.

Transnasal Endoscopic Pituitary Surgery-The Role of a CT Scan in Individual Tailoring of Posterior Septum Size Resection.

OBJECTIVE: This study was designed to evaluate the possibility of predicting the minimum size of septal resection for safe tumor extraction in transnasal paraseptal pituitary adenoma resection from preoperative computed tomography scans. METHODS: A retrospective CT scan analysis was performed on 20 patients who underwent endoscopic pituitary surgery at the University Hospital in Ostrava. Virtual insertion of the straight instrument into the sphenoid cavity was simulated using a CT scan. The minimum septal resection size was predicted and compared to various diameters in the nasal cavity. The results were then compared with cadaveric dissections, in which septal resections were performed at 1 cm and 2 cm distances from the anterior sphenoid wall. The association between cadaver dissections and CT scan results was studied. RESULTS: A total of 20 patients who underwent endoscopic transnasal surgery for pituitary adenoma between the years 2020 and 2021 were enrolled in the study. The mean virtual posterior septal size resection needed to reach the medial edge of the ICA with the straight instrument, without infracturing the nasal septum, was 13.2 mm. In cadavers with a 1 cm posterior septal resection, the medial edge of the ICA was reached with the straight instrument. In 2 cm resections, it was possible to reach beyond the lateral edge of the ICA. CONCLUSION: There is no significant correlation between the minimum septal size resection and measured diameters in the nasal cavity. According to our study, a 1 cm resection is sufficient for a non-extended pituitary tumor extraction. More extensive septal resections allow for better maneuverability and overview in the surgical field.

Does Bicanalicular Intubation Improve the Outcome of Endoscopic Dacryocystorhinostomy?

The aim of this study was to compare the success of endoscopic dacryocystorinostomy with and without bicanalicular intubation in the treatment of distal nasolacrimal duct obstruction. METHODS: In a prospective, randomized, comparative study, endoscopic dacryocystorinostomy without bicanalicular silicone intubation (Group I) and endoscopic dacryocystorinostomy with intubation (Group II) were performed in patients with distal nasolacrimal duct obstructions. The tubes were removed 3 months after surgery in Group II, and the patients were followed up for 6 months after surgery. Therapeutic success was defined as the fluorescein dye disappearance test grade 0-1 corresponding with a complete resolution of symptoms. RESULTS: Thirty patients, aged 23-86 years, were included in the study. The success rate was 13/15 (86.67%) in Group I and in 14/15 (93.33%) in Group II. The difference between the two groups was not statistically significant (p = 0.483). Most common complications were granulations that occurred in 1/15 (6.67%) patient in Group I and in 2/15 (13.33%) patients in Group II. Adhesions in rhinostomy with epiphora and persistent secretion were observed in 1/15 (6.67%) patient in Group II. CONCLUSIONS: Bicanalicular intubation does not significantly increase the success rate of EDCR in distal nasolacrimal obstruction in adults.

Epiglottopexy Is a Treatment of Choice for Obstructive Sleep Apnea Caused by a Collapsing Epiglottis.

Drug-induced sleep endoscopy (DISE) reveals epiglottic collapse to be a frequent cause of obstructive sleep apnea (OSA) and intolerance of positive airway pressure (PAP). These patients require different management. This prospective study aimed to compare transoral laser epiglottopexy outcomes in patients with OSA caused by epiglottic collapse with the patients' previous PAP outcomes. Fifteen consecutive adult patients with OSA and epiglottic collapse during DISE were included; ten were analyzed. Before inclusion, PAP was indicated and ineffective in six patients, one of whom underwent unsuccessful uvulopalatopharyngoplasty. PAP was performed during DISE in all patients before epiglottopexy and was uniformly ineffective. ENT control was performed at 1 week and 1 month, and control limited polygraphy to 6 months after surgery. The apnea−hypopnea index (AHI) and Epworth Sleepiness Scale (ESS) were significantly improved (p < 0.001 and p = 0.003, respectively) in all patients after epiglottopexy. Surgery was successful in 9/10 patients; the remaining patient had a significantly decreased AHI and could finally tolerate PAP. Transoral laser epiglottopexy is used to treat OSA in patients with epiglottic collapse. Unlike other methods, it significantly reduces both AHI and ESS and should be considered for these patients. An active search for OSA patients with epiglottic collapse is recommended to prevent treatment failure.

Computational Fluid Dynamics Could Enable Individualized Surgical Treatment of Nasal Obstruction (A Preliminary Study).

Passage of nasal airflow during breathing is crucial in achieving accurate diagnosis and optimal therapy for patients with nasal disorders. Computational fluid dynamics (CFD) is the dominant method for simulating and studying airflow. The present study aimed to create a CFD nasal airflow model to determine the major routes of airflow through the nasal cavity and thus help with individualization of surgical treatment of nasal disorders. The three-dimensional nasal cavity model was based on computed tomography scans of the nasal cavity of an adult patient without nasal breathing problems. The model showed the main routes of airflow in the inferior meatus and inferior part of the common meatus, but also surprisingly in the middle meatus and in the middle part of the common nasal meatus. It indicates that the lower meatus and the lower part of the common meatus should not be the only consideration in case of surgery for nasal obstruction in our patient. CFD surgical planning could enable individualized precise surgical treatment of nasal disorders. It could be beneficial mainly in challenging cases such as patients with persistent nasal obstruction after surgery, patients with empty nose syndrome, and patients with a significant discrepancy between the clinical findings and subjective complaints.

Internal Carotid Injury during Skull Base Surgery-Case Report and a Review of the Literature.

Iatrogenic injury of the internal carotid artery (ICA) is a rare, and probably underreported, complication of transnasal endoscopic skull base surgery. Although treatment algorithms have been suggested, there is no definite consensus or guideline for the management of this severe complication. We describe a case of ICA injury that occurred during a transsphenoidal biopsy of a tumor in the cavernous sinus and we present a treatment algorithm for managing this complication. We reviewed the articles published from 1998 to 2021, reporting on major vascular injury during transnasal endoscopic skull base surgery and endonasal endoscopic surgery, and we compare the methods and results of ICA injury management reported in the literature with the presented case. The most promising treatment for ICA injury might be packing with a muscle graft initially, then performing an endovascular intervention.

Sleep Endoscopy with Positive Airway Pressure: A Method for Better Compliance and Individualized Treatment of Patients with Obstructive Sleep Apnea.

In this study, we aimed to observe the effects of positive airway pressure (PAP) on individual levels of obstruction during drug-induced sleep endoscopy (DISE) of the upper airways (UA), to evaluate at which pressures the obstruction disappeared or worsened, and to identify cases in which PAP was ineffective. This prospective study was conducted from June 2018 to June 2022. PAP testing was performed during DISE in patients with moderate and severe OSA. The pressure was gradually increased over the range from 6.0 to 18.0 hPa. Our findings were evaluated using the VOTE classification. The examination was performed in 56 patients, with a median apnea-hypopnea index (AHI) of 26.4. Complete obstruction of the soft palate was observed in 51/56 patients (91%), oropharyngeal obstruction in 15/56 patients (27%), tongue base obstruction in 23/56 patients (41%), and epiglottic collapse in 16/56 patients (29%). PAP was most effective in cases of complete oropharyngeal obstruction, and least effective in cases of epiglottic collapse, where it was ineffective in 11/16 patients. DISE with PAP is a simple diagnostic method that can be helpful for identifying anatomic and dynamic reasons for PAP intolerance. The main indication is ineffective PAP treatment.

Monocanalicular versus bicanalicular intubation in the treatment of congenital nasolacrimal duct obstruction.

BACKGROUND: To compare the success rate of monocanalicular intubation (MCI) compared with bicanalicular silicone intubation (BCI) in congenital nasolacrimal duct obstruction (CNLDO) in infants and toddlers. METHODS: In a prospective, nonrandomized, comparative study, MCI (n = 35 eyes) through the inferior canaliculus or BCI (n = 35 eyes) were performed under general anaesthesia in children aged 10 to 36 months with CNLDO. The tubes were removed 3-4 months after tube placement, and the children were followed up for 6 months after the removal of tubes. Therapeutic success was defined as the fluorescein dye disappearance test grade 0-1, corresponding with a complete resolution of previous symptoms. Partial success was defined as improvement with some residual symptoms. RESULTS: Complete and partial improvement was achieved in 31/35 (88.57%) in the BCI group and 34/35 (97.14%) in the MCI group. The difference between the two groups was not significant (p = 0.584). Complications occurred in both groups. Dislodgement of the tube and premature removal was observed in four BCI cases, and loss of the tube was observed twice in the MCI group. Canalicular slitting was observed in five eyes in the BCI group. Granuloma pyogenicum observed in 2 cases with MCI revealed a few weeks after the tube removal. Corneal erosion in the inferior medial quadrant was observed in one MCI eye and revealed in a few days after the local treatment without tube removal. CONCLUSIONS: Both MCI and the BCI are effective methods for treating CNLDO. MCI has the advantage of a lower incidence of canalicular slit and easy placement.

Errors associated with the concentration of epinephrine in endonasal surgery.

This paper presents two cases of using erroneous concentrations of epinephrine during endonasal surgery. The two patients discussed were part of a larger study aimed at monitoring the absorption of epinephrine upon injection into the nasal mucosa. During this study, we observed major cardiovascular reactions in two consecutive patients--ventricular tachycardia with ventricular extrasystole and a significant rise in systolic and diastolic blood pressure and pulse rate. This state required pharmacological intervention. In hindsight, it was found that an erroneous application of ten times higher (1:10,000) concentration of epinephrine than the usual was injected. The applied solution was prepared in our institutional pharmacy and was labelled incorrectly (1:100,000 instead of 1:10,000). The authors have analysed the steps leading to the erroneous applications and recommend safety precautions for the prevention of errors in the concentration levels of epinephrine. Epinephrine injections in concentrations of 1:10,000, followed by analyses of epinephrine levels in venous blood, have not yet been described in available literature.

Tonsillar origin of deep neck infection as a negative prognostic factor for developing complications.

<b>Aim:</b> The aim of this study was to compare the odontogenic and tonsillar origins of deep neck infection (DNI) as a negative prognostic factor for developing complications. </br></br> <b>Methods:</b> This was a retrospective study of 544 patients with tonsillar and odontogenic origins of DNI treated between 2006 and 2015 at 6 ENT Departments and Departments of Oral and Maxillofacial Surgery. Complications from DNI (descending mediastinitis, sepsis, thrombosis of the internal jugular vein, pneumonia, and pleuritis) were evaluated in both groups and compared. Associated comorbidities (cardiovascular involvement, hepatopathy, diabetes mellitus respiratory involvement, gastroduodenal involvement) were reviewed. </br></br> <b>Results:</b> Five hundred and forty-four patients were analyzed; 350/544 males (64.3%) and 19/544 females (35.7%). There were 505/544 cases (92.8%) with an odontogenic origin and 39/544 cases (7.2%) with a tonsillar origin of DNI. Complications occurred more frequently in the group with tonsillar origin of DNI (P < 0.001). There was no difference in diabetes mellitus between the two groups. </br></br> <b>Conclusions:</b> Currently, the tonsillar origin of DNI occurs much less frequently; nevertheless, it carries a much higher risk of developing complications than cases with an odontogenic origin. We recommend that these potentially high-risk patients with a tonsillar origin of deep neck infections should be more closely monitored.