Medial superior olive in the rat: Anatomy, sources of input and axonal projections.

Although rats and mice are among the preferred animal models for investigating many characteristics of auditory function, they are rarely used to study an essential aspect of binaural hearing: the ability of animals to localize the sources of low-frequency sounds by detecting the interaural time difference (ITD), that is the difference in the time at which the sound arrives at each ear. In mammals, ITDs are mostly encoded in the medial superior olive (MSO), one of the main nuclei of the superior olivary complex (SOC). Because of their small heads and high frequency hearing range, rats and mice are often considered unable to use ITDs for sound localization. Moreover, their MSO is frequently viewed as too small or insignificant compared to that of mammals that use ITDs to localize sounds, including cats and gerbils. However, recent research has demonstrated remarkable similarities between most morphological and physiological features of mouse MSO neurons and those of MSO neurons of mammals that use ITDs. In this context, we have analyzed the structure and neural afferent and efferent connections of the rat MSO, which had never been studied by injecting neuroanatomical tracers into the nucleus. The rat MSO spans the SOC longitudinally. It is relatively small caudally, but grows rostrally into a well-developed column of stacked bipolar neurons. By placing small, precise injections of the bidirectional tracer biotinylated dextran amine (BDA) into the MSO, we show that this nucleus is innervated mainly by the most ventral and rostral spherical bushy cells of the anteroventral cochlear nucleus of both sides, and by the most ventrolateral principal neurons of the ipsilateral medial nucleus of the trapezoid body. The same experiments reveal that the MSO densely innervates the most dorsolateral region of the central nucleus of the inferior colliculus, the central region of the dorsal nucleus of the lateral lemniscus, and the most lateral region of the intermediate nucleus of the lateral lemniscus of its own side. Therefore, the MSO is selectively innervated by, and sends projections to, neurons that process low-frequency sounds. The structural and hodological features of the rat MSO are notably similar to those of the MSO of cats and gerbils. While these similarities raise the question of what functions other than ITD coding the MSO performs, they also suggest that the rat MSO is an appropriate model for future MSO-centered research.

The nuclei of the lateral lemniscus: unexpected players in the descending auditory pathway.

Introduction: In the mammalian auditory pathway, the nuclei of the lateral lemniscus (NLL) are thought to be exclusively involved in the bottom-up transmission of auditory information. However, our repeated observation of numerous NLL neurons labeled after injection of retrograde tracers into the superior olivary complex (SOC) led us to systematically investigate with retrograde tracers the descending projections from the NLL to the SOC of the rat. Methods: We performed large injections of FluoroGold into the SOC to determine NLL contributions to descending projections, and focal injections of biotinylated dextran amine (BDA) to pinpoint the specific nuclei of the SOC innervated by each NLL. Results: The SOC is innervated by thousands of neurons distributed across four nuclei or regions associated with the lateral lemniscus: the ipsilateral ventral and intermediate nuclei of the lateral lemniscus (VNLL and INLL); the medial paralemniscal region (PL) of both sides; and the ipsilateral semilunar nucleus (SLN), a previously unrecognized nucleus that wraps around the INLL dorsally, medially, and caudally and consists of small, flat neurons. In some experiments, at least 30% of neurons in the VNLL and INLL were retrogradely labeled. All nuclei of the SOC, except the medial and lateral superior olives, are innervated by abundant lemniscal neurons, and each SOC nucleus receives a unique combination of lemniscal inputs. The primary target of the projections from the VNLL is the ventral nucleus of the trapezoid body (VNTB), followed by the superior paraolivary nucleus (SPON), and the medial nucleus of the trapezoid body (MNTB). The INLL selectively innervates the VNTB. The PL innervates dorsal periolivary regions bilaterally. The SLN preferentially innervates the MNTB and may provide the first identified non-calyceal excitatory input to MNTB neurons. Discussion: Our novel findings have strong implications for understanding acoustic information processing in the initial stages of the auditory pathway. Based on the proportion of lemniscal neurons involved in all the projections described, the NLL should be considered major players in the descending auditory pathway.

Ruptura de quiste hidatídico hepático hacia cavidad torácica por trauma tóraco-abdominal. Dificultades en el diagnóstico / Rupture of a hepatic hydatid cyst towards the chest cavity after an abdominal-chest trauma. Difficulties in the diagnosis

RESUMEN La equinococosis es una infección zoonótica causada por el cestodo del género Echinococcus, endémica en muchas regiones del Perú. Los quistes hidatídicos habitualmente se ubican en el hígado y pulmón, siendo infrecuente tanto su localización en otros órganos como la hidatidosis múltiple. La mayoría de ellos son asintomáticos y de hallazgo incidental, aunque también pueden ocurrir complicaciones, como su ruptura espontánea o traumática que tiene una mínima incidencia (3-17%), siendo insólito que se dé hacia el tórax. Se presenta el caso de un paciente con ruptura de quistes hidatídicos hepáticos hacia la cavidad pleural, por traumatismo tóraco-abdominal, que al constituir una presentación excepcional de la patología originó dificultades en su reconocimiento inicial teniéndose como diagnóstico diferencial un hemotórax masivo. Este finalmente fue superado por la revisión de imágenes tomográficas con las que se concluyó una hidatidosis hepática complicada.

SUMMARY Cystic hydatidosis is a zoonotic infection caused by the cestode Echinococcus, which is endemic in many regions of Peru. Hydatid cysts are usually located in the liver and lungs, locations elsewhere are rare as well as multiple hydatidosis. Most of the hydatid cysts are asymptomatic and are found incidentally. Rare complications may arise such as spontaneous or traumatic rupture (3-17%), it is very infrequent that the hydatid cyst rupture towards the chest wall. We present a case of a patient who suffered the rupture of hepatic cysts into the pleural cavity after an abdominal-chest trauma, the rarity of this event made the identification of the problem more difficult to be confused with massive hemothorax. Careful review of the CT-Scan images allowed to reach the correct diagnsosis.

Reconstrucción temprana en el tórax inestable con sistema de osteosíntesis torácico: Reporte de caso / Early unstable chest reconstruction with thoracic osteosynthesis: A case report

Se presenta el caso de un paciente varón con tórax inestable. Esta lesión es una entidad poco común que puede ser originada por múltiples traumatismos de alto impacto. El diagnóstico se estableció por signos clínicos y estudios de imágenes. El paciente recibió tratamiento quirúrgico con un sistema de osteosíntesis costal (StraCos®); se discuten los resultados obtenidos y sugerencias para casos de este tipo. (AU)

We present the case of a male patient with unstable chest, which is a rare entity that may be caused by high impact trauma. The diagnosis was stablished by clinical manifestations and image results. The patient received surgical treatment with a rib osteosynthesis. We discussed the results obtained and propose suggestions to manage this kind of patients. (AU)

Octopus Cells in the Posteroventral Cochlear Nucleus Provide the Main Excitatory Input to the Superior Paraolivary Nucleus.

Auditory streaming enables perception and interpretation of complex acoustic environments that contain competing sound sources. At early stages of central processing, sounds are segregated into separate streams representing attributes that later merge into acoustic objects. Streaming of temporal cues is critical for perceiving vocal communication, such as human speech, but our understanding of circuits that underlie this process is lacking, particularly at subcortical levels. The superior paraolivary nucleus (SPON), a prominent group of inhibitory neurons in the mammalian brainstem, has been implicated in processing temporal information needed for the segmentation of ongoing complex sounds into discrete events. The SPON requires temporally precise and robust excitatory input(s) to convey information about the steep rise in sound amplitude that marks the onset of voiced sound elements. Unfortunately, the sources of excitation to the SPON and the impact of these inputs on the behavior of SPON neurons have yet to be resolved. Using anatomical tract tracing and immunohistochemistry, we identified octopus cells in the contralateral cochlear nucleus (CN) as the primary source of excitatory input to the SPON. Cluster analysis of miniature excitatory events also indicated that the majority of SPON neurons receive one type of excitatory input. Precise octopus cell-driven onset spiking coupled with transient offset spiking make SPON responses well-suited to signal transitions in sound energy contained in vocalizations. Targets of octopus cell projections, including the SPON, are strongly implicated in the processing of temporal sound features, which suggests a common pathway that conveys information critical for perception of complex natural sounds.

Organization of the Zone of Transition between the Pretectum and the Thalamus, with Emphasis on the Pretectothalamic Lamina.

The zone of transition between the pretectum, derived from prosomere 1, and the thalamus, derived from prosomere 2, is structurally complex and its understanding has been hampered by cytoarchitectural and terminological confusion. Herein, using a battery of complementary morphological approaches, including cytoarchitecture, myeloarchitecture and the expression of molecular markers, we pinpoint the features or combination of features that best characterize each nucleus of the pretectothalamic transitional zone of the rat. Our results reveal useful morphological criteria to identify and delineate, with unprecedented precision, several [mostly auditory] nuclei of the posterior group of the thalamus, namely the pretectothalamic lamina (PTL; formerly known as the posterior limitans nucleus), the medial division of the medial geniculate body (MGBm), the suprageniculate nucleus (SG), and the ethmoid, posterior triangular and posterior nuclei of the thalamus. The PTL is a sparsely-celled and fiber rich flattened nucleus apposed to the lateral surface of the anterior pretectal nucleus (APT) that marks the border between the pretectum and the thalamus; this structure stains selectively with the Wisteria floribunda agglutinin (WFA), and is essentially immunonegative for the calcium binding protein parvalbumin (PV). The MGBm, located medial to the ventral division of the MGB (MGBv), can be unequivocally identified by the large size of many of its neurons, its dark immunostaining for PV, and its rather selective staining for WFA. The SG, which extends for a considerable caudorostral distance and deviates progressively from the MGB, is characterized by its peculiar cytoarchitecture, the paucity of myelinated fibers, and the conspicuous absence of staining for calretinin (CR); indeed, in many CR-stained sections, the SG stands out as a blank spot. Because most of these nuclei are small and show unique anatomical relationships, the information provided in this article will facilitate the interpretation of the results of experimental manipulations aimed at the auditory thalamus and improve the design of future investigations. Moreover, the previously neglected proximity between the MGBm and the caudal region of the scarcely known PTL raises the possibility that certain features or roles traditionally attributed to the MGBm may actually belong to the PTL.

Different tonotopic regions of the lateral superior olive receive a similar combination of afferent inputs.

The mammalian lateral superior olive (LSO) codes disparities in the intensity of the sound that reaches the two ears by integrating ipsilateral excitation and contralateral inhibition, but it remains unclear what particular neuron types convey acoustic information to the nucleus. It is also uncertain whether the known conspicuous morphofunctional differences and gradients along the tonotopic axis of the LSO relate to qualitative and/or quantitative regional differences in its afferents. To clarify these issues, we made small, single injections of the neuroanatomical tracer biotinylated dextran amine (BDA) into different tonotopic regions of the LSO of albino rats and analyzed the neurons labeled retrogradely in brainstem auditory nuclei. We demonstrate that the LSO is innervated tonotopically by four brainstem neuron types: spherical bushy cells and planar multipolar neurons of the ipsilateral ventral cochlear nucleus, principal neurons of the ipsilateral medial nucleus of the trapezoid body, and small multipolar neurons of the contralateral ventral nucleus of the trapezoid body. Unexpectedly, the proportion of labeled neurons of each type was virtually identical in all cases, thus indicating that all tonotopic regions of the LSO receive a similar combination of inputs. Even more surprisingly, our data also suggest that the representation of frequencies in the LSO differs from that of the nuclei that innervate it: compared to the latter nuclei, the LSO seems to possess a relatively larger portion of its volume devoted to processing frequencies in the lower-middle part of the spectrum, and a relative smaller portion devoted to higher frequencies. J. Comp. Neurol. 524:2230-2250, 2016. © 2015 Wiley Periodicals, Inc.

All the way from the cortex: a review of auditory corticosubcollicular pathways.

Enrico Mugnaini has devoted part of his long and fruitful neuroscientific career to investigating the structural similarities between the cerebellar cortex and one of the first relay stations of the mammalian auditory pathway: the dorsal cochlear nucleus. The hypothesis of the cerebellar-like nature of the superficial layers of the dorsal cochlear nucleus received definitive support with the discovery and extensive characterization in his laboratory of unipolar brush cells, a neuron type unique to certain regions of the cerebellar cortex and to the granule cell domains of the cochlear nuclei. Paradoxically, a different line of research carried out in his laboratory revealed that, unlike the mammalian cerebellar cortex, the dorsal cochlear nucleus receives direct projections from the cerebral cortex, a fact that constitutes one of the main differences between the cerebellum and the dorsal cochlear nucleus. In an article published in 1995, Mugnaini's group described in detail the novel direct projections from the rat auditory neocortex to various subcollicular auditory centers, including the nucleus sagulum, the paralemniscal regions, the superior olivary complex, and the cochlear nuclei (Feliciano et al., Auditory Neuroscience 1995; 1:287-308). This review gives Enrico Mugnaini credit for his seminal contribution to the knowledge of auditory corticosubcollicular projections and summarizes how this growing field has evolved in the last 20 years.

The dorsal tectal longitudinal column (TLCd): a second longitudinal column in the paramedian region of the midbrain tectum.

The tectal longitudinal column (TLC) is a longitudinally oriented, long and narrow nucleus that spans the paramedian region of the midbrain tectum of a large variety of mammals (Saldaña et al. in J Neurosci 27:13108-13116, 2007). Recent analysis of the organization of this region revealed another novel nucleus located immediately dorsal, and parallel, to the TLC. Because the name "tectal longitudinal column" also seems appropriate for this novel nucleus, we suggest the TLC described in 2007 be renamed the "ventral tectal longitudinal column (TLCv)", and the newly discovered nucleus termed the "dorsal tectal longitudinal column (TLCd)". This work represents the first characterization of the rat TLCd. A constellation of anatomical techniques was used to demonstrate that the TLCd differs from its surrounding structures (TLCv and superior colliculus) cytoarchitecturally, myeloarchitecturally, neurochemically and hodologically. The distinct expression of vesicular amino acid transporters suggests that TLCd neurons are GABAergic. The TLCd receives major projections from various areas of the cerebral cortex (secondary visual mediomedial area, and granular and dysgranular retrosplenial cortices) and from the medial pretectal nucleus. It densely innervates the ipsilateral lateral posterior and laterodorsal nuclei of the thalamus. Thus, the TLCd is connected with vision-related neural centers. The TLCd may be unique as it constitutes the only known nucleus made of GABAergic neurons dedicated to providing massive inhibition to higher order thalamic nuclei of a specific sensory modality.

Connections of the Superior Paraolivary Nucleus of the Rat: II. Reciprocal Connections with the Tectal Longitudinal Column.

The superior paraolivary nucleus (SPON), a prominent GABAergic center of the mammalian auditory brainstem, projects to the ipsilateral inferior colliculus (IC) and sends axons through the commissure of the IC (CoIC). Herein we demonstrate that the SPON is reciprocally connected with the recently discovered tectal longitudinal column (TLC). The TLC is a long and narrow structure that spans nearly the entire midbrain tectum longitudinally, immediately above the periaqueductal gray matter (PAG) and very close to the midline. Unilateral injections of biotinylated dextran into the SPON of the rat label abundant terminal fibers in the TLC of both sides, with an ipsilateral predominance. The SPON provides a dense innervation of the entire rostrocaudal extent of the ipsilateral TLC, and a relatively sparser innervation of the caudal and rostral portions of the contralateral TLC. SPON fibers reach the TLC by two routes: as collaterals of axons of the CoIC, and as axons that circumvent the ipsilateral IC before traveling in the deep layers of the superior colliculus (SC). The density of these projections identifies SPON as a significant source of input to the TLC. Other targets of the SPON discovered in this study include the deep layers of the SC and the PAG. The same experiments reveal numerous labeled cell bodies in the TLC, interspersed among the labeled SPON fibers. This observation suggests that the SPON is a significant target of TLC projections. The discovery of novel reciprocal connections between the SPON and the TLC opens unexpected avenues for investigation of sound processing in mammalian brainstem circuits.

Auditory response properties of neurons in the tectal longitudinal column of the rat.

The newly-discovered tectal longitudinal column (TLC) spans the paramedian region of the mammalian tectum. It has connections with several nuclei of the auditory system. In this report, we provide the first detailed description of the responses of TLC neurons to auditory stimuli, including monaural and binaural tones and amplitude modulated tones. For comparison, responses in the inferior colliculus (IC) were also recorded. Neurons in the TLC were sensitive to similar ranges of frequency as IC neurons, could have comparably low thresholds, and showed primarily excitatory responses to stimulation of the contralateral ear with either phasic or sustained response patterns. Differences of TLC compared to IC neurons included broader frequency tuning, higher average threshold, longer response latencies, little synchronization or rate tuning to amplitude modulation frequency and a smaller degree of inhibition evoked by stimulation of the ipsilateral ear. These features of TLC neurons suggest a role for the TLC in descending auditory pathways.

The TLC: a novel auditory nucleus of the mammalian brain.

We have identified a novel nucleus of the mammalian brain and termed it the tectal longitudinal column (TLC). Basic histologic stains, tract-tracing techniques and three-dimensional reconstructions reveal that the rat TLC is a narrow, elongated structure spanning the midbrain tectum longitudinally. This paired nucleus is located close to the midline, immediately dorsal to the periaqueductal gray matter. It occupies what has traditionally been considered the most medial region of the deep superior colliculus and the most medial region of the inferior colliculus. The TLC differs from the neighboring nuclei of the superior and inferior colliculi and the periaqueductal gray by its distinct connections and cytoarchitecture. Extracellular electrophysiological recordings show that TLC neurons respond to auditory stimuli with physiologic properties that differ from those of neurons in the inferior or superior colliculi. We have identified the TLC in rodents, lagomorphs, carnivores, nonhuman primates, and humans, which indicates that the nucleus is conserved across mammals. The discovery of the TLC reveals an unexpected level of longitudinal organization in the mammalian tectum and raises questions as to the participation of this mesencephalic region in essential, yet completely unexplored, aspects of multisensory and/or sensorimotor integration.

A model for auditory brain stem implants: bilateral surgical deafferentation of the cochlear nuclei in the macaque monkey.

BACKGROUND: Patients with extensive bilateral lesions of the auditory nerve have a profound and irreversible sensorineural hearing loss (SNHL), which can only be overcome with individually-fitted auditory brain stem implants that directly stimulate the cochlear nuclei. Despite the enormous potential of this increasingly applied treatment, the auditory performance of many implanted patients is limited, and the variability between cases hinders a complete understanding of the role played by the multiple parameters related to the efficacy of the implant. OBJECTIVES: To mimic the condition of patients who have bilateral lesions of the auditory nerve, we developed an experimental model of bilateral deafferentation of the cochlear nuclei by surgical transection of the cochlear nerves of adult primates. MATERIALS AND METHODS: We performed bilateral transection of the cochlear nerves of six adult, healthy, male captive-bred macaques (Macaca fascicularis). Before surgery, brain stem auditory evoked potentials were recorded. The histological material obtained from these animals was compared with similarly processed sections from seven macaques with intact cochlear nerves. The surgical technique, similar to that used in human neuro-otology, combined a labyrinthectomy and a neurectomy of the cochlear nerves, and caused deafness. We analyzed immunocytochemically the expression in cochlear nerve fibers of neurofilaments (SMI-32), and cytosolic calcium binding proteins calretinin, parvalbumin and calbindin, and also applied a histochemical reaction for acetylcholinesterase. RESULTS: None of the primates had any major complications due to the surgical procedure. The lesions produced massive anterograde degeneration of the cochlear nerves, evidenced by marked gliosis and by loss of both type I fibers (which in this species are immunoreactive for calretinin, parvalbumin and neurofilaments) and type II fibers (which are acetylcholinesterase positive). The model of surgical transection described herein causes extensive damage to the cochlear nerves while leaving the cochlea intact, thus mimicking the condition of patients with profound SNHL due to bilateral cochlear nerve degeneration. CONCLUSIONS: The phylogenetic proximity of primates to humans, and the paramount advantage of close anatomical and physiological similarities, allowed us to use the same surgical technique applied to human patients, and to perform a thorough evaluation of the consequences of neurectomy. Thus, bilateral surgical deafferentation of the macaque cochlear nuclei may constitute an advantageous model for study of auditory brain stem implants.

Quilotorax no traumático: Reporte de un caso / Non-traumatic chylothorax: A case report

Se presenta el caso de una paciente mujer con quilotórax no traumático. Esta enfermedad es una condición poco común que puede ser originada por múltiples desórdenes. El diagnóstico se estableció por estudio del líquido pleural y la toma de biopsias. La paciente recibió tratamiento no quirúrgico y quirúrgico, se discuten los resultados obtenidos y sugerencias para casos de este tipo.

Ventana torácica en el tratamiento del empiema pleural crónico en el Hospital Nacional Cayetano Heredia, 1990-1998 / Open window thoracostomy in the management of chronic empyema at the Hospital Nacional Cayetano Heredia. 1990-1998

Objetivo: Describir los resultados de la ventana torácica en el manejo del empiema pleural. Pacientes y métodos: Estudio descriptivo, retrospectivo y transversal. Se incluyeron pacientes sometidos a ventana torácica (toracostomía) entre 1990-1998, en el Hospital nacional Cayetano Heredia. Se estudió el tratamiento quirúrgico (técnica, hallazgos y complicaciones), morbilidad y mortalidad. De los 59 casos estudiados 39 (66.1 por ciento) fueron varones y 20 (33.9 por ciento) mujeres. La edad promedio fue 30.9 ñ 14 años. Resultados: Según la etiología, 55.93 por ciento tuvieron empiema pleural tuberculoso, 28.81 por ciento empiema post cirugía pulmonar, 11.86 por ciento empiema post neumónico y 3.39 por ciento empiema por traumatismo. El 95 por ciento de los casos fueron previamente drenados con tubo de toracostomía. El patrón radiológico predominante fue el hidroneumotórax (58 por ciento). El 64.4 por ciento fueron intervenidos bajo anestesia regional. El tiempo promedio operatorio fue de 57.3 ñ 28 minutos. Los arcos costales resecados con más frecuencia fueron el 6§-7§ (25 por ciento). El tiempo promedio de hospitalización fue 38.6 ñ 26.9 días, el tiempo promedio postoperatorios fue 8.5 ñ 8.3 días. De los pacientes que tuvieron un seguimiento mayor a 3 meses (33 pacientes), se pudo confirmar el cierre de la ventana torácica en 13 casos y reexpansión pulmonar en 21 casos. Conclusiones: La indicación principal fue la falta de respuesta al tubo de toracostomía de drenaje (40 por ciento). La etiología principal es el empiema pleural tuberculoso. Es un procedimiento ideal para pacientes severamente comprometidos e inmunosuprimidos. Las complicaciones postoperatorias fueron 11.86 por ciento. El porcentaje de reoperaciones fue de 3.4 por ciento. No se encontró mortalidad asociada al procedimiento.

Unbiased stereological estimates of neuron number in subcortical auditory nuclei of the rat.

The mammalian auditory system consists of a large number of cell groups, each containing its own complement of neuronal cell types. In recent years, much effort has been devoted to the quantitation of auditory neurons with common morphological, connectional, pharmacological or functional features. However, it is difficult to place these data into the proper quantitative perspective due to our lack of knowledge of the number of neurons contained within each auditory nucleus. To this end, we have employed unbiased stereological methods to estimate neuron number in the cochlear nuclei, superior olivary complex, lateral lemniscus, inferior colliculus and medial geniculate body. Additionally, we generated a three-dimensional model of the superior olivary complex. The utility of unbiased stereological estimates of auditory nuclei is discussed in the context of various experimental paradigms.

Tratamiento quirúrgico de la hidatidosis pulmonar en el Hospital Nacional Cayetano Heredia 1989 - 1999 / Surgical treatment of pulmonary hydatid cyst at the Hospital Nacional Cayetano Heredia 1989 - 1999

Objetivo: describir los resultados del tratamiento quirúrgico de pacientes con hidatidosis pulmonar. Pacientes y métodos: Estudio descriptivo, retrospectivo y transversal. Se incluyeron pacientes operados por hidatidosis pulmonar entre 1989 - 1999 en el Hospital Nacional Cayetano Heredia. Se registró el tipo de tratamiento quirúrgico (técnica, hallazgos y complicaciones), las manifestaciones clínicas, morbilidad y mortalidad. Se incluyeron en el estudio 84 pacientes sometidos a 88 intervenciones quirúrgicas. la distribución por sexos fue igual. La edad promedio fue 32.89 mas menos 18.63 años y el 77.4 por ciento de los pacientes procedía de Lima. Las manifestaciones clínicas más frecuentes fueron tos (86.9 por ciento), dolor torácico (50 por ciento) y murmullo vesicular disminuido (69 por ciento). El tiempo promedio de enfermedad fue 323 días. La positividad con doble difusión arco quinto fue de 61 por ciento y con Ester Blot, 70 por ciento. Resultados: las técnicas más utilizadas fueron parasitectomía capitonaje (28.4 por ciento) y lobectomía (28.4 por ciento). Los quistes únicos fueron 82.1 por ciento y los múltiples 17.8 por ciento. El pulmón derecho fue más afectado (59.6 por ciento). Los quistes entre 5-10 cm. fueron 51.5 por ciento y mayores de 10 cm. fueron 27.3 por ciento. Los quistes complicados fueron 75 por ciento. Tuvieron control al alta 71.43 por ciento de pacientes hallándose en un paciente un nuevo quiste en el hemitórax previamente operado. Conclusiones: la mortalidad fue 4.7 por ciento. Las técnicas más utilizadas fueron parasitectomía capitonaje y lobectomía. La cirugía radical estuvo asociada con mayor número de complicaciones intraoperatorias. Las complicaciones postoperatorias mayores fueron 28.4 por ciento. El porcentaje de reoperaciones fue 12.5 por ciento.