Maribacter halichondriae sp. nov., isolated from the marine sponge Halichondria panicea, displays features of a sponge-associated life style.

A new member of the family Flavobacteriaceae (termed Hal144T) was isolated from the marine breadcrumb sponge Halichondria panicea. Sponge material was collected in 2018 at Schilksee which is located in the Kiel Fjord (Baltic Sea, Germany). Phylogenetic analysis of the full-length Hal144T 16S rRNA gene sequence revealed similarities from 94.3 to 96.6% to the nearest type strains of the genus Maribacter. The phylogenetic tree of the 16S rRNA gene sequences depicted a cluster of strain Hal144T with its closest relatives Maribacter aestuarii GY20T (96.6%) and Maribacter thermophilus HT7-2T (96.3%). Genome phylogeny showed that Maribacter halichondriae Hal144T branched from a cluster consisting of Maribacter arenosus, Maribacter luteus, and Maribacter polysiphoniae. Genome comparisons of strain Maribacter halichondriae Hal144T with Maribacter sp. type strains exhibited average nucleotide identities in the range of 75-76% and digital DNA-DNA hybridisation values in the range of 13.1-13.4%. Compared to the next related type strains, strain Hal144T revealed unique genomic features such as phosphoenolpyruvate-dependent phosphotransferase system pathway, serine-glyoxylate cycle, lipid A 3-O-deacylase, 3-hexulose-6-phosphate synthase, enrichment of pseudogenes and of genes involved in cell wall and envelope biogenesis, indicating an adaptation to the host. Strain Hal144T was determined to be Gram-negative, mesophilic, strictly aerobic, flexirubin positive, resistant to aminoglycoside antibiotics, and able to utilize N-acetyl-ß-D-glucosamine. Optimal growth occurred at 25-30 °C, within a salinity range of 2-6% sea salt, and a pH range between 5 and 8. The major fatty acids identified were C17:0 3-OH, iso-C15:0, and iso-C15:1 G. The DNA G + C content of strain Hal144T was 41.4 mol%. Based on the polyphasic approach, strain Hal144T represents a novel species of the genus Maribacter, and we propose the name Maribacter halichondriae sp. nov. The type strain is Hal144T (= DSM 114563T = LMG 32744T).

Micromonospora tarapacensis sp. nov., a bacterium isolated from a hypersaline lake.

Strain Llam7T was isolated from microbial mat samples from the hypersaline lake Salar de Llamará, located in Taracapá region in the hyper-arid core of the Atacama Desert (Chile). Phenotypic, chemotaxonomic and genomic traits were studied. Phylogenetic analyses based on 16S rRNA gene sequences assigned the strain to the family Micromonosporaceae with affiliation to the genera Micromonospora and Salinispora. Major fatty acids were C17 : 1ω8c, iso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The cell walls contained meso-diaminopimelic acid and ll-2,6 diaminopimelic acid (ll-DAP), while major whole-cell sugars were glucose, mannose, xylose and ribose. The major menaquinones were MK-9(H4) and MK-9(H6). As polar lipids phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and several unidentified lipids, i.e. two glycolipids, one aminolipid, three phospholipids, one aminoglycolipid and one phosphoglycolipid, were detected. Genome sequencing revealed a genome size of 6.894 Mb and a DNA G+C content of 71.4 mol%. Phylogenetic analyses with complete genome sequences positioned strain Llam7T within the family Micromonosporaceae forming a distinct cluster with Micromonospora (former Xiangella) phaseoli DSM 45730T. This cluster is related to Micromonospora pelagivivens KJ-029T, Micromonospora craterilacus NA12T, and Micromonospora craniellae LHW63014T as well as to all members of the former genera Verrucosispora and Jishengella, which were re-classified as members of the genus Micromonospora, forming a clade distinct from the genus Salinispora. Pairwise whole genome average nucleotide identity (ANI) values, digital DNA-DNA hybridization (dDDH) values, the presence of the diamino acid ll-DAP, and the composition of whole sugars and polar lipids indicate that Llam7T represents a novel species, for which the name Micromonospora tarapacensis sp. nov. is proposed, with Llam7T (=DSM 109510T,=LMG 31023T) as the type strain.

Classification of parotidectomies: a proposal of the European Salivary Gland Society.

The objective of this study is to provide a comprehensive classification system for parotidectomy operations. Data sources include Medline publications, author's experience, and consensus round table at the Third European Salivary Gland Society (ESGS) Meeting. The Medline database was searched with the term "parotidectomy" and "definition". The various definitions of parotidectomy procedures and parotid gland subdivisions extracted. Previous classification systems re-examined and a new classification proposed by a consensus. The ESGS proposes to subdivide the parotid parenchyma in five levels: I (lateral superior), II (lateral inferior), III (deep inferior), IV (deep superior), V (accessory). A new classification is proposed where the type of resection is divided into formal parotidectomy with facial nerve dissection and extracapsular dissection. Parotidectomies are further classified according to the levels removed, as well as the extra-parotid structures ablated. A new classification of parotidectomy procedures is proposed.

Optimizing bacteriophage treatment of resistant Pseudomonas.

Phage therapy is increasing in relevance as an alternative treatment to combat antibiotic resistant bacteria. Phage cocktails are the state-of-the-art method of administering phages in clinical settings, preferred over monophage treatment because of their ability to eliminate multiple bacterial strains and reduce resistance formation. In our study, we compare monophage applications and phage cocktails to our chosen method of phage sequential treatments. To do so, we isolated four novel bacteriophages capable of infecting Pseudomonas alcaligenes T3, a close relative of P. aeruginosa, and characterized them using sequencing and transmission electron microscopy. While investigating monophage treatments, we observed that different phage concentrations had a strong impact on the timing and amount of resistance formation. When using phage cocktails, we observed that P. alcaligenes were capable of forming resistance in the same timespan it took them to become resistant to single phages. We isolated mutants resistant to each single phage as well as mutants exposed to phage cocktails, resulting in bacteria resistant to all four phages at once. Sequencing these mutants showed that different treatments yielded unique single nucleotide polymorphism mutation patterns. In order to combat resistance formation, we added phages one by one in intervals of 24 h, thus managing to delay resistance development and keeping bacterial growth significantly lower compared to phage cocktails.IMPORTANCEWHO declared antimicrobial resistance a top threat to global health; while antibiotics have stood at the forefront in the fight against bacterial infection, the increasing number of multidrug-resistant bacteria highlights a need to branch out in order to address the threat of antimicrobial resistance. Bacteriophages, viruses solely infecting bacteria, could present a solution due to their abundance, versatility, and adaptability. For this study, we isolated new phages infecting a fast-mutating Pseudomonas alcaligenes strain capable of forming resistance within 30 h. By using a sequential treatment approach of adding one phage after another, we were able to curb bacterial growth significantly more compared to state-of-the-art phage cocktails.

Gene expression signatures and molecular markers associated with clinical outcome in locally advanced head and neck carcinoma.

The purpose of this study was to identify molecular markers associated with tumor recurrence and survival in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). We studied the expression profile of 63 pre-treatment tumor biopsies obtained from locally advanced HNSCCs treated with standard treatments. Cluster analysis identified three tumor subtypes associated with significant differences in local recurrence-free survival (LRFS) (P<0.001), progression free-survival (PFS) (P<0.009) and overall survival (OS) (P<0.004). Tumor subtype 1, associated with short LRFS, PFS and OS, showed features of epithelial-mesenchymal transition and undifferentiation. It also overexpressed genes involved in cell adhesion, NF-κB and integrin signalling. Tumor subtype 3, associated with longer LRFS, PFS and OS, showed a high degree of differentiation and overexpressed genes located in chromosomal regions 19q13 and 1q21. Tumor subtype 2, which had an intermediate clinical outcome between subtype 1 and subtype 3, overexpressed genes involved in branching morphogenesis. Finally, we validated the association between gene cluster classification and patient survival using Gene Set Enrichment Analysis and two HNSCC data sets obtained from two independent patient cohorts. In conclusion, we generated a gene prognostic signature associated with survival in locally advanced patients using the expression profile of the pre-treatment tumor biopsy. Independent prospective studies would be necessary to assess if the proposed survival signature could help to guide clinical management of HNSCC.

Pharyngocutaneous fistula in irradiated patients: systematic review and our experience.

OBJECTIVE: Radiotherapy is considered a risk factor for pharyngocutaneous fistula after a total laryngectomy. This study aimed to analyse the impact of exclusive radiotherapy versus chemoradiotherapy and the time interval between radiotherapy and surgery on the risk of pharyngocutaneous fistula. METHOD: This study was a retrospective revision of 171 patients treated with a total laryngectomy after radiotherapy or chemoradiotherapy. RESULTS: Pharyngocutaneous fistula occurred in 33 patients (19.3 per cent). Patients previously treated with chemoradiotherapy showed a non-significant higher pharyngocutaneous fistula rate compared with patients treated with radiotherapy (25.0 per cent vs 18.0 per cent; p = 0.455). Patients with a pharyngocutaneous fistula after chemoradiotherapy treatment required a surgical repair more frequently than patients treated with radiotherapy (p = 0.005). There were no significant differences in the pharyngocutaneous fistula rate depending on the time interval between radiotherapy and surgery (p = 0.580). CONCLUSION: There were no differences in the pharyngocutaneous fistula rate after total laryngectomy depending on the previous treatment with radiotherapy or chemoradiotherapy, or depending on the interval between radiotherapy treatment and surgery.

Adaptive lifestyle of bacteria determines phage-bacteria interaction.

Bacteriophages and their interactions with microbes are not well understood. As a first step toward achieving a better understanding, we isolated and sequenced the Curvibacter phage PCA1 for the purpose of eliminating Curvibacter sp. AEP1.3, the main colonizer of Hydra vulgaris AEP. Our experiments showed that PCA1 phage caused a strong, virulent infection only in sessile Curvibacter sp. AEP1.3 but was unable to infect planktonic and host-associated bacterial cells of the same strain. In an effort to investigate this phenomenon, we compared sessile, planktonic, and host-associated bacteria via RNA sequencing and found that all three states differed significantly in their expression patterns. This finding led us to propose that the adaptive lifestyle of Curvibacter sp. AEP1.3 results in varying degrees of susceptibility to bacteriophage infection. This concept could be relevant for phage research and phage therapy in particular. Finally, we were able to induce phage infection in planktonic cells and pinpoint the infection process to a membrane protein. We further identified potential phage-binding protein candidates based on expression pattern analysis.

Salvage surgery after locoregional failure in head and neck carcinoma patients treated with chemoradiotherapy.

With the increasing use of concomitant chemoradiotherapy (CCRT) in the treatment of advanced head and neck carcinoma, surgery has lost ground as the first therapy and is reserved as a salvage treatment in cases of locoregional failure. The objective of our study was to review our experience in patients who had a local or regional recurrence after treatment with CCRT. Thirty-two patients underwent salvage surgery after CCRT: 24 were treated with a local or locoregional resection and 8 patients with a neck dissection only. In patients who had surgery involving the primary location of the tumor, some kind of reconstruction was required in 83% of cases. One or more postoperative complications occurred in nine patients. The median hospital stay was 18.5 days. There was a significant difference in hospital stay in relation to the appearance of surgical complications. Five-year adjusted survival after salvage surgery was 34.2% (CI 95% 13.2-55.2%). Adjusted survival was related to the status of the resection margins and appearance of neck nodes with extracapsular spread in the neck dissection. In conclusion, salvage surgery after CCRT involves extensive resections, requiring reconstruction techniques with regional or microanastomosed free flaps in most cases, achieving acceptable outcomes.

The carotid axis revisited.

The aim was to determine the variations in the level of origin of carotid bifurcation and diameters of the common, internal, and external carotid arteries which is clinically important for several interventional procedures. Therefore, 165 human embalmed corpses were dissected. The data collected were analyzed using the Chi square-test and the Pearson correlation test. The results of previous studies have been reviewed. In relation to the level of the carotid bifurcation, taking as a reference point the hyoid bone, the values ranged from 4 cm below the hyoid body to 2.5 cm above the body of the hyoid, being the average height-0.33 cm, with a standard deviation of 1.19 cm. The right carotid bifurcation was established at a higher level (x = - 0.19 cm.) than the left one (x = - 0.48 cm.) (p = 0.046). On the contrary, no significant gender differences could be observed. The arterial calibres of the common and internal carotid arteries were higher in male than female. In the internal carotid artery (X = 0.76 cm.), the left was greater than the right (X = 0.72 cm.) (P = 0.047). However, no differences in the distribution of the calibre of the external carotid artery were found neither by side nor gender. Variations in the level of bifurcation and calibres of carotid arteries are relevant for interventional radiology procedures and head and neck surgeries. Knowledge of these anatomical references might help clinicians in the interpretation of the carotid system.

Predictive value of transcriptional expression of Krüppel-like factor-6 (KLF6) in head and neck carcinoma patients treated with radiotherapy.

PURPOSE: To analyse the relationship between the transcriptional expression of Krüppel-like factor-6 (KLF6) and local response to treatment with radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC). METHODS: We determined the transcriptional expression of KLF6 in tumour biopsies obtained before treatment with radiotherapy in 83 HNSCC patients. The KLF6 expression was categorized according to the local control of the disease with a recursive partitioning analysis. RESULTS: During the follow-up period, 27 patients (32.5%) had a local recurrence of the tumour. Patients with local recurrence had significantly higher levels of KLF6 expression than patients in which radiotherapy achieved local control of the disease (P = 0.029). Five-year local recurrence-free survival for patients with a high transcriptional expression of KLF6 (n = 46) was 51.1% (95% CI 36.4-66.2%), and for patients with low expression it was 85.6% (95% CI 73.9-97.3%) (P = 0.0001). The results of a multivariate analysis showed that patients with a high KLF6 expression had a 3.8 times higher risk of local recurrence after treatment with radiotherapy (95% CI 1.4-10.5, P = 0.008). CONCLUSION: Transcriptional expression of KLF6 was significantly related to local control in HNSCC patients treated with radiotherapy. Patients with high levels of KLF6 expression had a significantly higher risk of local recurrence after treatment.

High AAV vector purity results in serotype- and tissue-independent enhancement of transduction efficiency.

The purity of adeno-associated virus (AAV) vector preparations has important implications for both safety and efficacy of clinical gene transfer. Early-stage screening of candidates for AAV-based therapeutics ideally requires a purification method that is flexible and also provides vectors comparable in purity and potency to the prospective investigational product manufactured for clinical studies. The use of cesium chloride (CsCl) gradient-based protocols provides the flexibility for purification of different serotypes; however, a commonly used first-generation CsCl-based protocol was found to result in AAV vectors containing large amounts of protein and DNA impurities and low transduction efficiency in vitro and in vivo. Here, we describe and characterize an optimized, second-generation CsCl protocol that incorporates differential precipitation of AAV particles by polyethylene glycol, resulting in higher yield and markedly higher vector purity that correlated with better transduction efficiency observed with several AAV serotypes in multiple tissues and species. Vectors purified by the optimized CsCl protocol were found to be comparable in purity and functional activity to those prepared by more scalable, but less flexible serotype-specific purification processes developed for manufacture of clinical vectors, and are therefore ideally suited for pre-clinical studies supporting translational research.

Epidemiology of human papillomavirus-related oropharyngeal cancer in a classically low-burden region of southern Europe.

The incidence of human papillomavirus (HPV)-related oropharyngeal cancer is increasing in some regions. Nevertheless, the epidemiology of this disease has not been extensively investigated in southern Europe. We conducted a retrospective cohort study of patients diagnosed with primary oropharyngeal cancer from 1991 to 2016. Cancer tissues underwent histopathological evaluation, DNA quality control, HPV-DNA detection and p16INK4a immunohistochemistry. Data were collected from medical records. Factors associated with HPV positivity and time trends were evaluated with multivariable Bayesian models. The adjusted prevalence of HPV-related cases in 864 patients with a valid HPV-DNA result was 9.7%, with HPV-DNA/p16INK4a double positivity being considered. HPV-related oropharyngeal cancer was likely to occur in non-smokers and non-drinkers, to be located in the tonsil or diagnosed at advanced stages. Time-trend analysis showed an increasing risk of HPV-related oropharyngeal cancer in the most recent periods (5-year period increase of 30%). This increase was highest and with a clear increasing trend only in the most recent years (2012-2016). The prevalence of HPV-related oropharyngeal cancer started to sharply increase in the most recent years in our setting, as occurred two decades ago in areas where most oropharyngeal cancer cases are currently HPV-related. Our results provide a comprehensive assessment of the epidemiological landscape of HPV-related oropharyngeal cancer in a region of southern Europe.

Elective neck dissection during salvage surgery after radiotherapy in patients with head and neck squamous cell carcinoma.

SUMMARY: Elective neck dissection in patients with recurrent head and neck squamous cell carcinoma (HNSCC) without evidence of neck disease (crN0) is poorly defined. A retrospective review was carried out on 165 crN0 patients treated with salvage surgery and elective neck dissection. Multivariate Cox analysis and recursive partitioning analysis were used to evaluate prognostic factors. The frequency of occult neck node metastases in the neck dissection (rpN+) was 16.4%. The risk of occult metastases for glottic rpT1-T2 recurrences was 5.9%, for glottic rpT3-T4 recurrences 13.2%, for non-glottic rpT1-T2 recurrences 16.1% and for locally advanced (rpT3-T4) non-glottic recurrences 31.1%. Patients with occult neck node metastases (rpN+) had a 5-year adjusted survival rate of 38.1%, while patients without nodal disease (rpN0) had a 5-year adjusted survival rate of 71.1% (p = 0.0001). Elective neck dissection can be omitted in crN0 patients with rT1-T2 glottic recurrence. We consider it advisable to perform elective neck dissection in all other situations.

Técnica quirúrgica con Zigoma quad con carga inmediata en maxilar atrófico: a propósito de un caso / Surgical technique with quad Zygoma with immediate loading in an atrophic maxilla: a case report

Introducción: En la actualidad existen técnicas quirúrgicas predecibles y reproducibles para los tratamientos en pacientes con atrofias de rebordes maxilares, los implantes cigomáticos son unas de las alternativas. El trabajo interdisciplinario entre el rehabilitador oral y el cirujano maxilofacial es fundamental para el éxito de la rehabilitación del paciente. El presente caso clínico reporta un paciente de sexo femenino de 60 años, sin antecedentes médicos, donde se observa en el conebean atrofia del reborde alveolar por lo que se planifica cuatro implantes cigomáticos. Objetivo: El objetivo del informe clínico es mostrar una alternativa de tratamiento quirúrgico implantologico en paciente con maxilar atrofiado. Resultados: Los resultados demostraron la eficacia de los implantes cigomáticos en pacientes edéntulos con atrofia del reborde alveolar más la colocación de una prótesis inmediata. Conclusión: Unas de las alternativas de tratamiento en maxilares con rebordes atróficos son la colocación de implantes cigomáticos junto a una buena planificación digital. varios estudios han descrito que la tasa de éxito de estos implantes es muy alta, debido a que la técnica es segura, reproducible y genera alta satisfacción en los pacientes. (AU)

Introduction: At present there are predictable and reproducible surgical techniques for treatments in patients with maxillary rim atrophy, zygomatic implants are one of the alternatives. The interdisciplinary work between the oral rehabilitator and the maxillofacial surgeon is fundamental for the success of the patient's rehabilitation. The present clinical case reports a 60 year old female patient, with no medical history, where atrophy of the alveolar ridge was observed in the conebean and four zygomatic implants were planned. Objective: The objective of the clinical report is to show an alternative implantological surgical treatment in a patient with atrophied maxilla. Results: The results demonstrated the efficacy of zygomatic implants in edentulous patients with alveolar ridge atrophy plus immediate prosthesis placement. Conclusion: One of the treatment alternatives in maxillae with atrophic rims is the placement of zygomatic implants together with a good digital planning. Several studies have described that the success rate of these implants is very high, due to the fact that the technique is safe, reproducible and generates high patient satisfaction, (AU)

Nasopharyngeal carcinoma: 30-year experience of a single institution in a non-endemic area.

PURPOSE: Over the past years, radiotherapy techniques have changed significantly. The impact of these changes in the management of nasopharyngeal carcinoma (NPC) has not been fully evaluated. METHODS/PATIENTS: Between 1984 and 2014, 223 NPC were diagnosed in our hospital. Prior to 2000, patients were treated with 2D treatment plan (RT2D) that evolved to 3D schemes thereafter (RT3D). RESULTS: Tumors in the RT3D period showed significantly lower stages than those in the RT2D period. 5-year cause-specific survival improved from 55.7% (95% CI: 46.7-64.7%) in the RT2D period to 78.7% (95% CI: 68.7-88.7%) in the RT3D period (P = 0.006). This difference was greater for non-keratinizing NPC, where specific survival went from 63.2% (95% CI: 52.2-74.2%) to 84.4% (95% CI: 74.4-94.4%) (P = 0.014). CONCLUSION: Recent changes in treatment strategies including concurrent chemoradiation and 3D radiotherapy may have impacted in better survival for NPC. Improved imaging techniques may have contributed by earlier detection and better treatment planning.

Detection and differentiation of Entamoeba histolytica and Entamoeba dispar in clinical samples through PCR-denaturing gradient gel electrophoresis.

Amebiasis is one of the twenty major causes of disease in Mexico; however, the diagnosis is difficult due to limitations of conventional microscopy-based techniques. In this study, we analyzed stool samples using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to differentiate between Entamoeba histolytica (pathogenic) and E. dispar (non-pathogenic). The target for the PCR amplification was a small region (228 bp) of the adh112 gene selected to increase the sensitivity of the test. The study involved 62 stool samples that were collected from individuals with complaints of gastrointestinal discomfort. Of the 62 samples, 10 (16.1%) were positive for E. histolytica while 52 (83.9%) were negative. No sample was positive for E. dispar. These results were validated by nested PCR-RFLP (restriction fragment length polymorphism) and suggest that PCR-DGGE is a promising tool to differentiate among Entamoeba infections, contributing to determine the specific treatment for patients infected with E. histolytica, and therefore, avoiding unnecessary treatment of patients infected with the non-pathogenic E. dispar.

A retrospective analysis of the outcome of patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck refractory to a platinum-based chemotherapy.

AIMS: Recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN) develops in around 72,000 people in Europe every year. Treatment options are limited, mainly consisting of platinum-based palliative chemotherapy, with median overall survival times of only 6-8 months. No standard second-line treatment after progression on platinum-based chemotherapy is available. Few data have reported the efficacy of these treatments and the outcome of the patients. In an effort to generate such data, this retrospective study analysed clinical records from 151 patients with SCCHN refractory to platinum-based chemotherapy treated between 1990 and 2000 at seven different centres around Europe. MATERIALS AND METHODS: Most patients (45%) received only best supportive care (BSC), and had a median survival of 56 days. A total of 28.5% of the patients received second-line chemotherapies: 16.6% radiotherapy and 9.9% chemoradiotherapy. RESULTS: No objective response was observed with the various second-line chemotherapies. The overall median survival was 103 days (95% confidence interval [CI]: 77-126 days) for the whole cohort. The overall objective response rate (ORR) to second-line treatment in this population was calculated to be 2.6%. CONCLUSION: These results highlight the need for additional treatment options for this disease. Similar, if not superior, response rates have already been observed in initial clinical studies of novel, targeted anti-cancer agents.

Can cure be achieved in patients with head and neck carcinomas? The problem of second neoplasm.

The improvement in locoregional control of head and neck carcinomas over the last few decades does not appear to modify the final survival of these patients, mainly due to the appearance of distant metastases and second neoplasms. This article reviews the topic of second neoplasm in patients with an index tumor in the head and neck, making a special point of the incidence and epidemiology of second neoplasms, the influence on prognosis, etiopathogenic theories and the possibility of prevention.

Foramen thyroideum: a comparative study in embryos, fetuses, and adults.

The incidence and characteristics of foramen thyroideum (FT) in embryonic and/or fetal larynges have not been established. In the present study, 90 adult larynges and 53 embryonic-fetal larynges were studied. The incidence of FT during the embryonic-fetal period (57%) was statistically different from the adult period (31%) (P = 0.005). All the FT found in the adult period contained vessels and/or nerves, while in the embryonic and fetal period only 63% presented neurovascular elements (P < 0.001). The origin of FT in the embryonic period and its persistence during adult life is discussed.

An anatomical study of anastomoses between the laryngeal nerves.

OBJECTIVE: To systematize the anatomy of the connecting branches between laryngeal nerves. METHODS: Microdissection of 90 larynges obtained from necropsies (57 men and 33 women; age range, 41-95 y). RESULTS: Anastomoses between the internal and recurrent nerves appeared in four different patterns: 1) Galen's anastomosis, as the connection between the dorsal branches of both nerves (100%); 2) arytenoid plexus, as the connection between the arytenoid branches of both nerves, in relation with the arytenoid muscle, and divided in a deep part (100%) and a superficial part (86%); 3) cricoid anastomosis, previously only described in cows, located in the front of the cricoid lamina (6/10 cases); and 4) thyroarytenoid anastomosis, as the connection of a descending branch of the internal laryngeal nerve and an ascending branch of the recurrent nerve (14%). Anastomosis between the internal laryngeal and the external laryngeal nerves appeared as a connecting branch throughout the foramen thyroideum (21%). Anastomosis between the external laryngeal and recurrent nerves appeared as a connecting branch throughout the cricothyroid muscle (68%). CONCLUSION: At least two anastomoses (Galen's anastomosis and arytenoid plexus) appeared in 21% of hemilarynges, and 79% of cases had three or more anastomoses between the laryngeal nerves. The different prevalence of this complex anastomotic pattern suggests functional differences in the sensory and motor innervation of individual subjects.